Critical Server Error after update, pretty new to grav

Updated Grav from older version (v1.0.10) to latest and now the site doesn't work. Cannot access front or backend.

php version in use after server update: 8.1.7

Please help!

Here's the info about the error:

Server Error

Sorry, something went terribly wrong!

0 - abs(): Argument #1 ($num) must be of type int|float, string given

For further details please review your logs/ folder, or enable displaying of errors in your system configuration.

@chukster1000, A flawless upgrade from Grav 1.0.10 to 1.7.41.1 could hardly be expected :-)

Also the issue may be one of the plugins, or the theme. They are probably as old as Grav 1.0.10 is...

• Did you upgrade the themes/plugins using the command prompt?
• What does the log file tell you?
  The stacktrace will give some hints as of where the error has been thrown.