Every error the compiler raises has a stable code, shown as `error[FV0602]` and in the `code`
field of `ferrovue --format json`. A code names one kind of refusal and is never given to another:
one the compiler stops raising stays listed here, marked retired. The first two digits are the
area. [`errors_and_limits`](crate::guide::errors_and_limits) explains what the compiler refuses
and why. A warning, such as one for a deprecated configuration key, has a code of its own, shown as
`warning[FV1117]` and with the `severity` `"warning"` in JSON.
This page is generated from the compiler's list in `packages/ferrovue/src/errors.ts` by
`pnpm errors:generate`; `pnpm test` fails when the two differ.
# Components and parsing: FV00xx
## FV0001
Source file that does not parse.
A `<script setup>` block, or a file it reads, is not valid TypeScript. The message is the parser's own, with the line and column where it stopped.
## FV0002
Component file Vue cannot parse.
## FV0003
`<script>` without `setup`.
## FV0004
Component without a `<template>`.
## FV0005
Template Vue cannot compile.
## FV0006
Unexpected construct in Vue's compiled template.
The compiler met output of Vue's server compiler that it has no translation for. Please report it with the component that caused it.
## FV0007
Component file name that gives no Rust module of its own.
Each component is written to a Rust module named after its file in snake case (`UserCard.vue` is `user_card.rs`). A file name that is not letters, digits and `_` starting with a letter, two names with the same snake case (`FooBar.vue` and `Foo_bar.vue`), `Mod.vue`, and a name a module ferrovue writes for the project already has (`Types.vue`, `Stores.vue`) are refused.
# Script setup: FV01xx
## FV0101
`inheritAttrs` that is not `true` or `false`.
## FV0102
`watch` with `immediate`.
## FV0103
Effect that runs once on the server.
## FV0104
`onServerPrefetch`.
## FV0105
Statement in setup that could change what renders.
## FV0106
`defineAsyncComponent` of anything but a component of this project.
## FV0107
Unsupported statement in setup.
## FV0108
`...rest` in destructured props.
## FV0109
Destructured prop that is not a plain name.
# Constants and enums: FV02xx
## FV0201
Constant that refers to itself.
## FV0202
Enum member without a value after a string member.
## FV0203
Enum member value that is not a string or number literal.
## FV0204
Field a constant object does not have.
## FV0205
Spread or hole in a constant list.
## FV0206
Computed or spread key in a constant object.
## FV0207
Constant that is not a literal.
## FV0208
Constant object read whole.
## FV0209
`null` in a constant list of plain values.
## FV0210
Constant list of plain values of different types.
## FV0211
Constant list mixing plain values and objects.
## FV0212
Two constant lists with one Rust name.
## FV0213
Object in a constant list without a required field.
## FV0214
`null` for a field that is not nullable.
## FV0215
Field of the wrong type in a constant list's object.
## FV0216
Field of an unsupported type in a constant list's objects.
## FV0217
Field that is only ever `null`.
## FV0218
Field `null` in some objects and absent in others.
## FV0219
Field of different types across a constant list's objects.
## FV0220
Constant list's object type declared twice.
## FV0221
Constant list's object type named as a Rust type.
## FV0222
Constant object read by a key chosen at run time.
# Props and types: FV03xx
See [`props`](crate::guide::props).
## FV0301
`generic` that is not a list of type parameters.
## FV0302
Type parameter without a constraint.
A generic component renders each type parameter as its constraint, so `generic="T"` alone gives the server no type. Write `generic="T extends string"`.
## FV0303
Props declared at run time.
## FV0304
Props type not declared in the component.
## FV0305
`defineModel` without a type.
## FV0306
`defineModel` of a nullable type that is not required.
## FV0307
Default for a nullable prop.
## FV0308
Unknown type.
## FV0309
Type that is only `undefined`.
## FV0310
Object type written in place.
## FV0311
Type that may be both `null` and `undefined`.
A Rust `Option` holds one kind of nothing, where JavaScript has two. Declare `T | null` or `x?: T`, never both. See [`props`](crate::guide::props#nullable-props).
## FV0312
Union of different types.
## FV0313
`Record` not keyed by `string`.
## FV0314
Type alias that refers to itself.
## FV0315
Unsupported named type.
## FV0316
Unsupported type.
## FV0317
`Record` of unsupported values.
## FV0318
Interface named as a Rust type.
## FV0319
Type declared in two files.
## FV0320
Interface with members other than plain named fields.
## FV0321
Optional field of a nullable type.
## FV0322
Prop default that is not a literal.
# Templates and attributes: FV04xx
See [`generated_code`](crate::guide::generated_code).
## FV0401
Interpolation of a value that is not a string, a number or a boolean.
## FV0402
Attribute value of an unsupported type.
## FV0403
Attribute bound to a value Vue's server leaves out.
Vue's server renderer leaves out an attribute bound to a list, an object or a `route.query` value, and hydration then sets it to the value's `String()` without reporting a mismatch. Join a list (`.join(",")`) or narrow a query value to one string.
## FV0404
Unsafe attribute name.
## FV0405
Custom directive not listed in `clientDirectives`.
A custom directive's `getSSRProps` may add attributes on the server, which ferrovue does not run. List a directive that adds none in `clientDirectives`.
## FV0406
`$attrs` on a root that takes scope ids.
## FV0407
Attributes that are not an object literal.
## FV0408
Computed or spread key in an attribute object.
## FV0409
`className` bound in place of `class`.
## FV0410
Merged attributes that are not object literals.
## FV0411
Class merged with a string that may repeat the class before it.
## FV0412
Fallthrough attribute of an unsupported type.
## FV0413
`v-model` comparing values of types it cannot compare.
## FV0414
`v-model` over an array.
## FV0415
Value read from `$attrs`.
## FV0416
Root `<Transition>` or `<KeepAlive>` around `v-if` that is given attributes.
## FV0417
Attribute name chosen at run time.
## FV0418
`<component :is>` over a value that is not a closed set.
`<component :is>` compiles to a `match` over its choices, so each one must be known when compiling: an imported component, an HTML element's name, a `computed` or `?:` choosing among them, a prop typed as a union of string literals, or an object of imported components read by such a prop. A `string`, a `Component` or a value from elsewhere could be anything.
## FV0419
`<component :is>` naming something other than an HTML element.
## FV0420
`<component :is>` over a prop that may be absent.
## FV0421
`<component :is>` reading a key its object does not have.
## FV0422
`v-html` or `v-text` on `<component :is>`.
## FV0423
`v-show`, or `v-model` on `<select>`, in content rendered from virtual nodes.
Inside an element `<component :is>` chooses, in the slot content such an element renders, and inside a `<RouterLink>`, Vue's server renders from virtual nodes, where `v-show` writes no `style` while it shows and `v-model` on a `<select>` marks no option `selected`. Bind `:style` or `:selected` yourself.
# Child components: FV05xx
See [`generated_code`](crate::guide::generated_code).
## FV0501
Child component that is not among the compiled components.
## FV0502
Fallthrough attribute that would reach a child's prop.
## FV0503
Child props that are not an object literal.
## FV0504
Computed or spread key in child props.
## FV0505
Attribute named by an integer.
## FV0506
Required prop not passed.
## FV0507
Required nullable prop not passed.
## FV0508
Attributes passed to a child that takes none.
## FV0509
String prop given a value that is not a string.
## FV0510
One type declared separately by parent and child.
## FV0511
Prop given a value of another type.
## FV0512
`Props` imported from a component that is not compiled.
## FV0513
Component resolved by name that is not imported.
## FV0514
Listener of unknown name given to a child with a prop named like a listener.
# Expressions: FV06xx
## FV0601
Name or function not available on the server.
## FV0602
Unsupported method.
## FV0603
Unsupported call.
## FV0604
Field read on a value that is not an object.
## FV0605
Field the type does not have.
## FV0606
Value that may be absent where its target cannot take it as it is.
## FV0607
Value of an unexpected type.
## FV0608
`+` between unsupported types.
## FV0609
Comparison between unsupported or absent values.
## FV0610
Spread or hole in an array literal.
## FV0611
Array literal of different types.
## FV0612
Computed member access.
## FV0613
Value set up in a way the server cannot evaluate.
## FV0614
Logical operator between values that are not booleans.
## FV0615
`??` falling back to a computed list.
## FV0616
`??` between different types.
## FV0617
`||` between unsupported types.
## FV0618
Unsupported unary operator.
## FV0619
`==` or `!=` with anything but `null` or `undefined`.
## FV0620
Loose test against `undefined` of a value of a plugin's type.
## FV0621
Comparison of a plugin's value with `null` or `undefined`.
## FV0622
`===` between different types.
## FV0623
Branches of `?:` of different types.
## FV0624
`new` in an expression.
## FV0625
Unsupported expression.
## FV0626
Strict test of a value that may be `null` or `undefined`.
## FV0627
Strict test against the absence a value cannot have.
## FV0628
`as` or `satisfies` stating a type the value does not have.
# Strings and numbers: FV07xx
See [`strings`](crate::guide::strings).
## FV0701
`Number()` of an unsupported value.
## FV0702
`parseInt()` or `parseFloat()` of a value that is not a string.
## FV0703
`parseInt()` with a radix other than a literal 10 or 16.
## FV0704
Unsupported `Math` method.
## FV0705
`.toFixed()` without a literal number of digits from 0 to 100.
## FV0706
String that may hold half of a surrogate pair compared, searched or joined.
`slice`, `substring`, `at`, `charAt` and `split("")` can cut a surrogate pair in half. JavaScript keeps the half where ferrovue holds U+FFFD, so two such strings may compare, search or join differently. See [`strings`](crate::guide::strings#halves-of-surrogate-pairs).
## FV0707
`JSON.stringify()` of an unsupported value.
## FV0708
Template literal of values that are not present strings, numbers or booleans.
## FV0709
String method with the wrong number of arguments.
## FV0710
Regular expression given to a string method.
## FV0711
String method given a value that is not a present string.
## FV0712
String method given a value that is not a present number.
## FV0713
Function given to a string method.
## FV0714
`.repeat()` by a negative or infinite count.
## FV0715
Case mapping by the server's locale.
# Lists and loops: FV08xx
See [`props`](crate::guide::props).
## FV0801
`.includes()` of a value of another type than the list's.
## FV0802
`.join()` with a separator that is not a string.
## FV0803
List method on a value that is not a list.
## FV0804
List method over a list of unsupported items.
## FV0805
List method given anything but an arrow function or `Boolean`.
## FV0806
Arrow function with a block body.
## FV0807
Arrow function index that is not a plain name.
## FV0808
Defaults or nested patterns in an arrow function's item.
## FV0809
Arrow function item bound by an unsupported pattern.
## FV0810
`.map()` to optional or unsupported values.
## FV0811
`.slice()` with more than two arguments.
## FV0812
`.slice()` of values that are not numbers.
## FV0813
List method given more than one function.
## FV0814
`Object` method of a value that is not a `Record`.
## FV0815
`Object.values()` of a record of lists.
## FV0816
`Object.entries()` outside a `v-for`.
## FV0817
Unsupported `Object` method.
## FV0818
`v-for` over `Object.entries()` without `[key, value]`.
## FV0819
`v-for` over an empty array literal.
## FV0820
`v-for` over a value that is not a list or a number.
## FV0821
Defaults or nested patterns in a `v-for` item.
## FV0822
`v-for` item bound by an unsupported pattern.
## FV0823
`v-for` key or index that is not a plain name.
# Slots: FV09xx
See [`slots`](crate::guide::slots).
## FV0901
Slots that are not an object literal.
## FV0902
Computed or spread slot name.
## FV0903
Content for a slot the child does not have.
## FV0904
Defaults or nested patterns in destructured slot props.
## FV0905
Slot props bound by an unsupported pattern.
## FV0906
Slot props taken from a slot that passes none.
## FV0907
Slot read that the template does not render.
## FV0908
Slot prop of a type with no Rust type.
## FV0909
Array literal as a slot prop.
## FV0910
Computed list as a slot prop.
## FV0911
Slot prop of an unsupported type.
## FV0912
Slot name that is not literal.
## FV0913
Slot props that are not attributes or an object literal.
## FV0914
Computed or spread key in slot props.
## FV0915
Slot prop name that is not a plain name.
## FV0916
Outlets of one slot that pass different props.
## FV0917
Interface named as a slot's props type.
## FV0918
Slot scope id given to content that takes none.
## FV0919
`<slot>` with fallback content inside an element `<component :is>` chooses.
Inside an element that `<component :is>` chooses, Vue renders a slot's content as virtual nodes and decides whether to show the fallback by rules of their own. Give the fallback from the parent instead.
## FV0920
`<slot>` rendered both inside and outside an element `<component :is>` chooses.
# Classes, styles and scoped styles: FV10xx
See [`scoped_styles`](crate::guide::scoped_styles).
## FV1001
Computed or spread key in a class object.
## FV1002
Computed class name that is not a string.
## FV1003
Class name with spaces around it.
## FV1004
Class binding of an unsupported type.
## FV1005
`<style module>` without `cssModules` in the configuration.
Vite names a CSS module's classes by `css.modules.generateScopedName`. ferrovue computes the same names when `cssModules` in `ferrovue.config.json` is set as that option is; without it, it cannot know them.
## FV1006
`v-bind()` in CSS of a value that is not a string or a number.
Vue's server writes a variable `v-bind()` sets from a string or a number, `initial` for `null` and `undefined`, and warns of anything else.
## FV1007
Style binding of an unsupported type.
## FV1008
Computed or spread key in a style object.
## FV1009
Style property named by a number or starting with `:`.
## FV1010
Style array mixing a string with objects.
## FV1011
Style property whose place depends on a condition.
## FV1012
Scope ids handed to a component whose render does not take them.
## FV1013
`class` written apart from a later `:class` in content rendered from virtual nodes.
Inside an element `<component :is>` chooses, in the slot content such an element renders, and inside a `<RouterLink>`, Vue's server renders from virtual nodes, where a static `class` written before `:class` keeps its place and its names come first. ferrovue writes them so when nothing stands between the two; with attributes between them, write the two next to each other, or `:class` first.
## FV1014
`<style module>` whose class names ferrovue cannot compute.
ferrovue names the classes of a CSS module written in the component in plain CSS, as postcss-modules does in Vite. A module in another file (`src`), one a preprocessor compiles (`lang`), and one that imports names from another file (`composes: x from "./a.css"`, `@value x from "./a.css"`) are refused.
## FV1015
`useCssModule` of a module the component does not declare.
# Configuration and helpers: FV11xx
See [`quick_start`](crate::guide::quick_start).
## FV1101
Helper called with the wrong number of arguments.
## FV1102
Configuration file not found.
## FV1103
Configuration file that is not valid JSON.
## FV1104
Configuration without `components` or `out`.
## FV1105
Unsupported `scopeId`.
## FV1106
`builders` that is not `true` or `false`.
## FV1107
Unknown helper type.
## FV1108
Imported function without a Rust twin.
## FV1109
Twin name that is not PascalCase.
## FV1110
Twin without `rust`.
## FV1111
Twin prop name that is not camelCase.
## FV1112
Twin slot name that is not a plain name.
## FV1113
Configuration that is not a JSON object.
## FV1114
Unknown configuration key.
A key ferrovue does not read is refused, as it is most often a misspelt one (`component` for `components`). The message names the key it most likely means.
## FV1115
Configuration value of the wrong type.
## FV1116
Directory the configuration names that cannot be read.
## FV1117
Deprecated configuration key.
A warning: ferrovue still reads the key, and stops reading it in the next major release. The message names what to write instead. A key is deprecated for at least one minor release before it is removed.
## FV1118
Deprecated command-line option.
A warning: the option still works, and is removed in the next major release. The message names what to use instead. An option is deprecated for at least one minor release before it is removed.
# Router: FV12xx
See [`routing`](crate::guide::routing).
## FV1201
Route parameter that is not a present string or number.
## FV1202
`to` that is not a string or an object literal.
## FV1203
Computed or spread key in a `to` object.
## FV1204
Unsupported key in a `to` object.
## FV1205
`query` that is not an object literal.
## FV1206
Computed or spread key in a query.
## FV1207
Query value that may be `null`.
## FV1208
`hash` that is not a string.
## FV1209
Route name that is not a string literal.
## FV1210
Unknown route name.
## FV1211
`params` that is not an object literal.
## FV1212
Computed or spread key in `params`.
## FV1213
Unknown route parameter.
## FV1214
Route parameter not given.
## FV1215
`to` with both `path` and `params`.
## FV1216
`path` that is not a string.
## FV1217
`to` without `name` or `path`.
## FV1218
`<RouterLink>` attributes that are not literal.
## FV1219
Computed or spread key in `<RouterLink>` attributes.
## FV1220
`custom` on `<RouterLink>`.
## FV1221
`href` or `aria-current` set on `<RouterLink>`.
## FV1222
`<RouterLink>` without `to`.
## FV1223
Element in a `<RouterLink>` given a slot scope id.
## FV1224
`<slot>` in a `<RouterLink>` that takes scope ids.
## FV1225
`<RouterLink>` without `routes` configured.
## FV1226
`<RouterLink>` attribute that is not a string literal.
## FV1227
Fallthrough attribute that would reach a `<RouterLink>` prop.
## FV1228
Fallthrough attribute that would replace a `<RouterLink>` attribute.
## FV1229
`<RouterLink>` slot other than the default.
## FV1230
Route read without `routes` configured.
## FV1231
Route field not available on the server.
## FV1232
Routes file that is not an array.
## FV1233
Route entry of an unsupported shape.
## FV1234
`typeof` of anything but a query value.
## FV1235
`??` after a query value with a fallback that is not a string.
## FV1236
`<RouterView>` in a component with `<style scoped>`.
## FV1237
`<RouterView>` in a child component.
## FV1238
`routes` that is neither a routes file nor `{ pages }`.
## FV1239
Pages folder that cannot be read.
## FV1240
Page file name the router cannot match.
Each part of a page's path is plain text (letters, digits, `-` and `_`) or one whole parameter: `[id]`, `[[id]]` (optional) or `[...path]` (a catch-all, last). A parameter beside text in one part (`prefix-[id].vue`), a repeatable parameter (`[id]+`), an optional catch-all (`[[...path]]`), a parameter parser (`[id=int]`) and a character code (`[x+2E]`) are not matched on the server.
## FV1241
Named view in a page file name.
## FV1242
`definePage()` in a page.
`definePage()` changes a page's route (its name, path, alias, meta or params) at build time. ferrovue builds the server's routes from the files' paths alone, so the two would disagree.
## FV1243
`<route>` block in a page.
## FV1244
`_parent.vue` with no pages to hold.
## FV1245
Page whose component name is taken or not a Rust name.
## FV1246
Routes file that cannot be read.
## FV1247
Routes file that is not valid JSON.
# Pinia stores: FV13xx
See [`pinia`](crate::guide::pinia).
## FV1301
Type declared by two stores.
## FV1302
Store id that is not a string literal.
## FV1303
Store of an unsupported shape.
## FV1304
Store `state` without a declared return type.
## FV1305
Store `getters` that is not an object literal.
## FV1306
Getter that is not a function of the state.
## FV1307
Setup store without a block body.
## FV1308
Unsupported statement in a setup store.
## FV1309
Setup store that does not return an object.
## FV1310
Setup store returning anything but plain names.
## FV1311
Setup store returning a name it does not declare.
## FV1312
Interface named as a setup store's state type.
## FV1313
`ref<T | null>()` without a value.
## FV1314
Setup store `ref` without a type.
## FV1315
Getter with a block body.
## FV1316
Getter that reads `this`.
## FV1317
Getter that returns a function.
## FV1318
Getters that read each other.
## FV1319
Store imported by anything but its `use…` hook.
## FV1320
`storeToRefs` of anything but a store bound in setup.
## FV1321
`storeToRefs` not destructured into plain names.
## FV1322
Store hook called with arguments.
# vue-i18n: FV14xx
See [`i18n`](crate::guide::i18n).
## FV1401
Locale file that is not valid JSON.
## FV1402
Locale message that does not parse.
## FV1403
Linked message with a key chosen at run time.
## FV1404
Linked message with an unknown modifier.
## FV1405
Locale message construct ferrovue does not render.
## FV1406
`t()` value that is not a present string, number or boolean.
## FV1407
`t()` without `i18n` configured.
## FV1408
`t()` with unsupported arguments.
## FV1409
`t()` key that is not a string.
## FV1410
Computed or spread key in `t()`'s named values.
## FV1411
Default message given to `t()`.
## FV1412
Plural number that is not an integer.
## FV1413
`useI18n()` not destructured into plain names.
# Raw HTML, client-only content, teleports and Rust twins: FV15xx
See [`errors_and_limits`](crate::guide::errors_and_limits).
## FV1501
Twin props that are not attributes or an object literal.
## FV1502
`v-html` of anything but a `TrustedHtml` prop.
`v-html` writes raw HTML, which ferrovue allows only from a type you mark as trusted. See [`escaping`](crate::guide::escaping).
## FV1503
`TrustedHtml` prop without `trustedHtml` configured.
## FV1504
Attributes on `<ClientOnly>`.
## FV1505
`<ClientOnly>` slot other than the default and `#fallback`.
## FV1506
Slot props taken from `<ClientOnly>`'s `#fallback`.
## FV1507
`<Teleport>` in slot content whose emptiness is decided at run time.
## FV1508
`<Teleport>` target that is not a string.
## FV1509
Twin prop of a type with no Rust type.
## FV1510
Twin for a component ferrovue compiles.
## FV1511
`<ClientOnly>` with a `#fallback` in content rendered from virtual nodes.
Inside an element `<component :is>` chooses, inside a `<RouterLink>` or a twin's slot, and in the slot content they render, Vue's server renders from virtual nodes, and `<ClientOnly>` writes an empty fragment there instead of its fallback, which the client then renders and reports as a mismatch. Leave out the `#fallback`, or move the `<ClientOnly>` outside that content.
## FV1512
`v-html` on an element whose content the browser rebuilds.
The browser's HTML parser moves markup written in a `<table>`, `<thead>`, `<tbody>`, `<tfoot>`, `<tr>` or `<colgroup>` out of the table, drops the tags written in a `<select>` or `<optgroup>`, and ends SVG or MathML at an HTML tag, so the page holds other nodes than the server wrote and hydration mismatches. Put `v-html` on a `<td>`, `<th>` or `<caption>`, write the options in the template, or use an HTML element inside a `<foreignObject>` or an `<mtext>`. See [`escaping`](crate::guide::escaping).
## FV1513
`v-html` in a `<p>` of HTML that may hold blocks.
A block tag in the HTML (`<p>`, `<ul>`, `<div>`) ends the `<p>` it is written in where the browser reads it. Type the prop `InlineHtml` from `ferrovue/types`, which is `ferrovue::InlineHtml` on the server and keeps only inline tags, or put the HTML in a `<div>`. Slot content placed into a child's `<p>` is not seen at compile time. See [`escaping`](crate::guide::escaping).
# Provide and inject: FV16xx
See [`provide_inject`](crate::guide::provide_inject).
## FV1601
Injection key that is not a string literal or a symbol exported from a `.ts` file.
## FV1602
Injection key symbol without an `InjectionKey<T>` type.
## FV1603
`provide` or `inject` with unsupported arguments.
## FV1604
`inject` that is not bound to a name at the top of `<script setup>`.
## FV1605
`inject(key)!`, asserting a provider.
## FV1606
`inject` of a string key with neither a default nor a type argument.
## FV1607
Function default without the factory flag.
## FV1608
Values of different types provided under one key.
## FV1609
Provided value that may be `null` or `undefined`.
## FV1610
Provided value of a form the context does not hold.
## FV1611
Object provided or given as a default under a key without an interface type.
## FV1612
Provided or default object whose fields do not match its interface.
## FV1613
Ref and plain value under one key.
## FV1614
Key provided twice by one component.
## FV1615
Two keys that give the context one field name.
## FV1616
`provide` in a component that holds `<RouterView>`.
The page `<RouterView>` shows is rendered from Rust and handed in as a slot, so it cannot see what the component provides. Provide the value above the router (in Rust, through the `Provides` the page is rendered with) or below it.
## FV1617
String-keyed `inject` inside a Rust twin's slot.
Content in a twin's slot is a child of the library component the twin stands for, which may provide the same string key on the client. Use an `InjectionKey` symbol, which only the project provides.
## FV1618
Setup that assigns to an injected value.
## FV1619
Function and value provided under one key.
## FV1620
`provide` or `inject` called inside an expression.
# Page head: FV17xx
See [`head`](crate::guide::head).
## FV1701
Options given to `useHead`.
## FV1702
Head input that is not an object literal.
## FV1703
Head key ferrovue does not translate.
## FV1704
Spread, computed key, hole or method in a head input.
## FV1705
Function in a head input.
unhead calls a function given as a value on the server only when it takes no arguments, as a getter (`title: () => props.title`), which ferrovue evaluates. A `titleTemplate` function and an event handler (`onload`) run with arguments or on the client.
## FV1706
Head value of a type the head does not take.
## FV1707
`tagPosition`, `tagPriority` or `tagDuplicateStrategy` that is not a literal it accepts.
## FV1708
`useHeadSafe`.
## FV1709
`useSeoMeta` key or value ferrovue does not translate.
## FV1710
`class` or `style` in the head that may be `null`.
unhead's server renderer throws on a `class` or `style` of `null`. Write `?? undefined`, which leaves the attribute out.
## FV1711
`innerHTML` or `textContent` on a head tag that has no content.