Docker version is 20.10.3 build 48d30b5, and the server is running CentOS 7, which doesn’t reach EOL until June next year but the kernel version (3.10.0-862.11.6.el7.x86_64) is one that doesn’t pass your checks as per this thread - though commenting the check out as per that thread has worked fine previously (even as recently as 3.2.0.beta4-dev (cdbe0f74e8) on a different forum on the same server). The forum with this issue is currently on 3.1.0.beta2 (I haven’t tried to upgrade the other forums which are on 3.2.0.beta4-dev yet).
The kernel is actually part of the reason why we’re moving to a new server, so shall I take a back up of this forum as it is (3.1.0.beta2) and restore that into a new Discourse install to see if that works? And then, if it’d be any help to you, come back to the old server and either upgrade Docker or the kernel to see whether the upgrade will work then?
Edit:
One thing I did notice was when I went to the admin/upgrade panel it took ages to refresh versions, then when I went to click on upgrade docker all I got was a blank screen (that’s when I tried ./launcher rebuild.
I’ve got another old discourse forum on this server and the same thing is happening here. This screengrab might be of help - it can’t find some docker files:
Edit 2:
Doing the same on a more recent forum (on same server) I don’t get the same errors when I go to /upgrade > upgrade docker (just Failed to register Service Worker: TypeError: NetworkError: Load failed in the sources tab of the browser tools).
So I am guessing it’s because they are older versions (but I thought whenever they are older version you usually upgrade to the next newest until we get to the latest release : /)