The issue is not really Total image itself, but the fact that you are restoring from an old backup, which contained a customization file for that airport you made very early after GSX L2 was released, which had a bug in the jetway logo selection logic, which used the same logos of the ground operators, instead of using the specific jetway logos, which are different.
We fixed the bug long ago, but your customization was made before that, is still contains the name of a non-existent jetway logo (NZ). You only had to remove the .INI file for that airport located under %APPDATA%\Virtuali\GSX, so if you customize it again, it will be remade with the now fixed logic.