Happened just now. Typed an issue description, picked an assignee, submitted it, browser was loading for several seconds and then saw a 500 error page. Upon hitting back button, it didn’t save my issue description.
Is there an issue with gitlab.com? I don’t see anything on the status page, but in the past, that page has been slow to show problems/outages.
Just tried again and it worked, so the issue may have passed.
you should refer to the log files and understand what actually happened there the 1st time.
Server errors could happen due to a myriad of reasons, some of which - application/OS/hardware misconfiguration, server bug, external resource issue, or something completely different.
Good luck.
@maxkovgan this was on gitlab.com, not a GitLab instance that I have any admin access to 
Sorry for the ambiguous message. In any case it’s long since resolved.