svelte/documentation/docs/98-reference/.generated/server-errors.md

async_local_storage_unavailable

The node API `AsyncLocalStorage` is not available, but is required to use async server rendering.

Some platforms require configuration flags to enable this API. Consult your platform's documentation.

await_invalid

Encountered asynchronous work while rendering synchronously.

You (or the framework you're using) called render(...) with a component containing an await expression. Either await the result of render or wrap the await (or the component containing it) in a <svelte:boundary> with a pending snippet.

dynamic_element_invalid_tag

`<svelte:element this="%tag%">` is not a valid element name — the element will not be rendered

The value passed to the this prop of <svelte:element> must be a valid HTML element, SVG element, MathML element, or custom element name. A value containing invalid characters (such as whitespace or special characters) was provided, which could be a security risk. Ensure only valid tag names are passed.

html_deprecated

The `html` property of server render results has been deprecated. Use `body` instead.

hydratable_clobbering

Attempted to set `hydratable` with key `%key%` twice with different values.

%stack%

This error occurs when using hydratable multiple times with the same key. To avoid this, you can:

• Ensure all invocations with the same key result in the same value
• Update the keys to make both instances unique

<script>
  import { hydratable } from 'svelte';

  // which one should "win" and be serialized in the rendered response?
  const one = hydratable('not-unique', () => 1);
  const two = hydratable('not-unique', () => 2);
</script>

invalid_csp

`csp.nonce` was set while `csp.hash` was `true`. These options cannot be used simultaneously.

invalid_csp_streaming

`csp.hash` cannot be used with `experimental.streaming`, since the streamed `<script>` tags cannot be known in advance. Use `csp.nonce` instead.

invalid_id_prefix

The `idPrefix` option cannot include `--`.

lifecycle_function_unavailable

`%name%(...)` is not available on the server

Certain methods such as mount cannot be invoked while running in a server context. Avoid calling them eagerly, i.e. not during render.

server_context_required

Could not resolve `render` context.

Certain functions such as Warp methods cannot be invoked outside of a render(...) or withWarp(...) call, such as at the top level of a module.

warp_context_already_rendered

`render(...)` was called more than once inside the same `withWarp(...)` call

Each withWarp call can only contain one render, since all the values added to Warp instances inside it are serialized into that render's output. If you need to render more than once, use a separate withWarp call for each render.

warp_context_nested

`withWarp(...)` cannot be called inside another `withWarp(...)` or `render(...)` call

warp_key_exists

Key `%key%` has already been set in `Warp` `%id%`%stack%

On the server, each key in a Warp can only be set once. Something may already have read the first value during the render, so replacing it would mean the client hydrates with different data than the server rendered with. Use getOrInsert or getOrInsertComputed if the value might already exist.

warp_method_unsupported

`warp.%method%(...)` is not supported on the server

Values added to a Warp on the server may already be in use (or on their way to the client), so they cannot be removed.

warp_serialization_failed

Failed to serialize data added to a `Warp`.

`Warp` can serialize anything [`uneval` from `devalue`](https://npmjs.com/package/devalue) can, including promises. To serialize other values, pass a `replacer` to `render` or `withWarp`.

Cause:
%stack%

warp_set_after_render

Cannot set key `%key%` in `Warp` `%id%` after its values have been serialized

Values can be added to a Warp until the rendered HTML has been generated, after which they can no longer be sent to the client.