Today I decided to update my phpBB installation from 3.2.11 to the latest 3.3.8 version and ran into a problem. Only ACP is accessible, while forum homepage throws an 503 error message. I tried switching PHP versions between 7.1 and 7.4, no success (switching to 8.x completely breaks everything, even ACP doesn't work then). I thought there was an issue with some of my extensions but that also failed to be true, all extensions I have installed are supposed to be compatible with 3.3.x.
Host: OVH shared hosting
Database: MySQL(i) 5.6.51-log
Currently used version of PHP: 7.1.33
EDIT:
Issue solved. Turned out the culprit was a custom PHP code which seems to be incompatible with phpBB 3.8.8.
Last edited by Mick on Fri Aug 19, 2022 8:13 am, edited 1 time in total.
Reason:Solved.
Then there must be something terribly wrong with my installation or my server. Well... looks like I will need to spend some time on investigating this.