- A dist-upgrade was performed from Ubuntu 14 to Ubuntu 16 using
- Plesk is inaccessible: 502 or 404 error is shown instead of login prompt.
The dist-upgrade was performed manually instead of using upgrade script, distributed with Plesk.
- Restore the server from backup;
- Perform an upgrade with using the following Knowledge Base article: Performing the dist-upgrade from Ubuntu 14 to to Ubuntu 16.
dist-upgrade from Ubuntu 14 to Ubuntu 16 is supported by Plesk Onyx only.