I'm updating all of my various sites today in anticipation of moving to a new server which only has PHP 8.x. I've not had a problem with my main site, which was IC 4.5.x or 4.6.x. All I had to do was start the upgrade, get an error pointing out that the PHP version (then 7.4) was too low. I changed the version on the server and restarted the upgrade.
I'm caught in a trap with one of my sites, though, which is on 4.4.6. When I start the upgrade I get the anticipated message informing me about the incorrect version, although this takes a different form from earlier: it's an error message telling me that I need to increase the PHP version.
The problem occurs when I change the PHP version on the server. With the other site I could recommence the update. With this one, however, I'm stuck in vicious cycle: anything I try in the ACP results in a 500 error, and I have to restore PHP to 7.4. Then when I attempt to upgrade, I get the error message, increase the PHP version, get my server error if I try anything, and repeat.
I'm not sure what the solution is. How do I work around the ACP informing me that I need to increase the PHP version to proceed if doing so then causes the site to crash?