Current state is not compatible with TYPO3 < 9.5
Following exception is thrown if using the Backen Module within non-admin user:
Core: Exception handler (WEB): Uncaught TYPO3 Exception: Call to a member function getIsoMapping() on null | Error thrown in file ..../htdocs/typo3conf/ext/lfeditor/Classes/Service/SysLanguageService.php in line 136. Requested URL: https://example.com/typo3/index.php?M=system_LfeditorLfeditor&moduleToken=--AnonymizedToken--
This happen afte refactoring of Classes/Service/SysLanguageService.php
for TYPO3 9.5 in commit 8da1a3fc
The Locales::initialize();
does not return anything prior TYPO3 9.
Please restrict at least featured Versions to TYPO3 >= 9 LTS