It is on a Linux hosted server. Everything was working up until the version of wordpress got updated, along with some plug-ins.
Changing the permalinks to default didn’t fix the issue.
I currently have the site under Maintenance Mode, so it isn’t available at the moment because I don’t want users accessing the ‘broken’ site. I have tried the site at different locations (home, work, etc.) using different computers and web browsers but still get the message.
In case this helps, I have also cleared my web browser cache and the site is using Buddypress.
[ Please do not bump, that’s not permitted here. ]