---
title: "Troubleshooting"
manual: "StyleX Connector"
version: "1.1"
permalink: "https://docs.typo3.org/permalink/skom/stylex-connector:troubleshooting@1.1"
source: "Troubleshooting/Index.rst"
rendered: "2026-11-01T18:26:19+00:00"
---

# Troubleshooting {#troubleshooting}

## No classes appear {#no-classes-appear}

Confirm that the sitepackage registers the manifest and that its generated
file exists at the registered path. In a Development context the connector
reports a missing registration or file as a PHP notice or warning. Rebuild the
frontend assets, then flush TYPO3 caches.

An unknown style key returns no classes. Enable `warnOnMissingKeys` and use a
Development context to see the available keys in the warning. Check spelling
and make sure the corresponding StyleX source file is imported by the Vite
entrypoint.

## Styles do not show during Vite development {#styles-do-not-show-during-vite-development}

Ensure the browser receives `/virtual:stylex.css` from the Vite server. See
[Vite and asset delivery](https://docs.typo3.org/permalink/skom/stylex-connector:vite-and-asset-delivery@1.1) for the runtime link example. The connector
resolves class names but does not serve CSS.

## Bootstrap or FSC wins the cascade {#bootstrap-or-fsc-wins-the-cascade}

Inspect the element's computed styles and the compiled selector. If Bootstrap
is unlayered, set `useCSSLayers: false` in the StyleX Vite plugin. If the
project uses named layers, make sure both stylesheets actually use the layer
order declared first in the consuming CSS build. See [Bootstrap and cascade layers](https://docs.typo3.org/permalink/skom/stylex-connector:bootstrap-and-cascade-layers@1.1).

## Fluid prints the ViewHelper expression {#fluid-prints-the-viewhelper-expression}

Check that the extension is active and that TYPO3 caches have been cleared
after installation. The extension registers the `stylex` namespace globally.
When a conditional uses a nested variable, assign it to an `f:variable` and
use that simple name as the `when` key.

## Manifest changes remain stale {#manifest-changes-remain-stale}

In Development, the cache lifetime is already zero. In other contexts, flush
TYPO3 caches after deploying a changed manifest or set an appropriate
`manifestCacheLifetime` in Extension Manager configuration.