Sofern du über die GUI aktualisiert hast, klingt Fehler 500 nach diesem Hinweis bezüglich Auto-Update:
https://forum.froxlor.org/index.php?/top…-and-much-more/
ZitatAttention: The auto-update feature is currently unavailable due to the archive taking a bit longer to extract and froxlor trying to redirect too soon thus leading to an internal server error. A quick reload does "fix" the problem but it's not very clean and therefore I removed the 0.10.0 release from the autoupdate server to avoid that. Please use the manual update options, see https://github.com/Froxlor/Froxlor/wiki