Publish-NAVApp fails with Language issue.

When running the PS command to publish the “Sales and Inventory Forecast”, the function fails.

Publish-NAVApp -Path D:\temp\SalesAndInventoryForecast.navx -ServerInstance DynamicsNAV100

Publish-NAVApp : Development Environment - Compile Object Errors:
[19464334] ‘Logon’ is not an option.The existing options are:Anmelden, Abmelden, Starten, Beenden, Schlie�en – Object: Codeunit 1852 Item Sales Forecast Scheduler

Version: NAV 10.0.16177

Development Environment, Language set to ENU. (all german language folders removed from program files,
fin.etx and fin.stx in program files replaced from ENU folder.

All ZUP files removed

So, for anyone having a similar issue, I found the solution:
The table Session Event (2000000111) was modified by a database upgrade due to a CU update (don’t ask which).
As it seems, the system also updated the OptionString values of the option fields with the OptionCaption value of the current language.

This causes no obvious issues as all references inside NAV objects are also changed and your system continues
But it looks like the NavApp format is somewhat text based and tries to compile the objects after import - here the problem started in this case.

Solution was to open a CRONUS database of the latest CU and export the objects from in there (Session Event, Media Set, Tenant Media Set). Then import them back into local database.