Why did my site change PHP version after I removed one?

Troubleshooting Websites and PHP phpfallbackmissing version

When an installed PHP version is removed, its sites move to the nearest lower version, or the nearest higher if none is lower, and move back on reinstall.

This is the designed fallback, not a failure. Without it, one site pointing at a removed version would stop the PHP configuration of every client on the node from being published.

What happens

• Sites move to the nearest lower installed version; if none is lower, to the nearest higher.
• What each site requested is remembered. Reinstalling the version brings those sites back to it by themselves.
• The advisor lists the affected sites and says which version they requested.

Steps

1. Open Server, Recommendations and find the finding about sites whose requested PHP is not installed.
2. Either reinstall that version, or change the sites to a version you do have, under Websites, site, PHP options.
3. Test the application on the version it is running now: code written for 8.1 usually runs on 8.0 better than on 8.3, but test it.

Last updated: 2026-10-10