XF 2.2 Occasional "Site is currently being upgraded" error messages

[Noma]

Hello,

my users have recently began receiving a "Site is currently being upgraded" error messages on random page loads. It happens at most once per user per session, and is always fixed with a reload. But nevertheless it's quite annoying. I haven't been able to reproduce the error myself so it's been quite difficult to debug.

But some facts:

• XenForo is at its latest version
• PHP 8.0
• The version in the database and in the codebase match
• No add-on is in the "processing" state
• Visiting the /install path doesn't show anything odd, no upgrade is in process
• I have a few other installs on the same server, and there hasn't been reports on the same problem.

Any idea how this could be fixed?

 

[Paul B]

The intermittent nature of it and the fact there isn't an actual upgrade in progress, sounds like a caching issue.

 

[Noma]

The intermittent nature of it and the fact there isn't an actual upgrade in progress, sounds like a caching issue.

I have an Nginx fastcgi cache in use, but I've purged it a few times now and the problem keeps coming back. So apparently there is some mechanism that produces the error message without a real need.