[Backport 12.4] Add hint for BE login problems#748

froemken merged 2 commits into12.4TYPO3-Documentation/TYPO3CMS-Tutorial-GettingStarted:12.4from

backport-747-to-12.4TYPO3-Documentation/TYPO3CMS-Tutorial-GettingStarted:backport-747-to-12.4Copy head branch name to clipboard