PHP Warning: Undefined global variable $TSFE in RenderPreProcessorHook.php line 81

[StanislavSeifert]

Got "Undefined global variable $TSFE" warning in backend:

It look like that $GLOBALS['TSFE'] will be initialized after the "renderPreProcessorProc" hook.

Enviroment:
TYPO3 Version: 11.5.17
Webserver: Apache/2.4.54 (Debian)
PHP Version: 8.1.11
wapplersystems/ws_less: "^11.0"

Following patch will solve the problem:

IDEA additional info:
Subsystem: com.intellij.openapi.diff.impl.patch.CharsetEP
<+>UTF-8
===================================================================
diff --git a/Classes/Hooks/RenderPreProcessorHook.php b/Classes/Hooks/RenderPreProcessorHook.php
--- a/Classes/Hooks/RenderPreProcessorHook.php
+++ b/Classes/Hooks/RenderPreProcessorHook.php	(date 1665767227441)
@@ -78,7 +78,9 @@

         $sitePath = Environment::getPublicPath() . '/';

-        $setup = $GLOBALS['TSFE']->tmpl->setup;
+        $configurationManager = GeneralUtility::makeInstance(\TYPO3\CMS\Extbase\Configuration\ConfigurationManager::class);
+        $setup = $configurationManager->getConfiguration(\TYPO3\CMS\Extbase\Configuration\ConfigurationManagerInterface::CONFIGURATION_TYPE_FULL_TYPOSCRIPT);
+
         if (\is_array($setup['plugin.']['tx_wsless.']['variables.'])) {

             $variables = $setup['plugin.']['tx_wsless.']['variables.'];

Please update this extension.

[danielDigitalArt]

Actually a fix exists (5493d62) but it was only included in version 12, thus there is currently no version available working on typo3 11.

On Typo3 11.5.33 i just installed Version 11.0 nd instantly got the same Error (PHP Warning: Undefined global variable $TSFE)

Solution would be to make a Version 11.0.1 which has this fix.