TYPO3 Exception 1312140065¶
Below, the TYPO3 community may have provided additional information or solutions for this exception. However, these may or may not apply to your particular case. If you can provide more information, you should come back here and add your experience and solution steps to this issue once you have resolved it.
General TYPO3 troubleshooting tips can be found in the section “Troubleshooting” of the menu, and live support is available in the TYPO3 Slack channel #typo3-cms.
(This exception happens only on very old TYPO3 versions - please consider updating your system to a secure version.)
You should use the following hook
$GLOBALS['TYPO3_CONF_VARS']['typo3/backend.php']['additionalBackendItems'] = filepath
t3lib_extMgm::addModuleCssFile in the above file.