For our Client, we have repaired a website based on CMS Joomla, which was damaged during an update crash.
During the repair, problems with various required server PHP versions were identified, all for the original site code, updated part and the installer, and during next steps, non-functioning friendly url, subpages of the front part and the administrator.
In practice, the website code present on the server and the database were an inconsistent mixture of at least 2 different Joomla versions.
The first stage of repair allowed for the completion of the update process, removal of the installer, selection of the appropriate version of the PHP interpreter, interface corrections, launching some of the non-functioning front pages available under friendly urls.
In the second stage, the consistency of the CMS code fragments after determining the closest center of gravity of the version was improved, and a phased database correction thanks to staged selective SQL query calls.
In case of similar problems or upgrading issues if you want to fix the update error, please contact: email@example.com