Help, Nextcloud web page error

Hello everyone, I need your help, my Nextcloud web page is not opening, after updating the jail to version 21 within the Freenas, I am running Nextcloud as jail on freenas, it was running fine for couple of months and suddenly today it was not accessible through the web, but I was able to ping the jail IP, after logging in to Freenas and updating the plugin, the webpage was up and accessible but it is showing an error, please help me to solve the issue.

This is your error. Search the web:

were not replaced correctly. Make sure it is a version compatible with the server.

Perhaps this is your solution:

Please check your version in config/config.php and
Use the correct versions.

Perhaps the update was no success and the apps are too new.
Perhaps the update was a success and the apps are the old apps from the old release.