SteamAPI_RestartApp [...] error message prevents game from starting when executing the game *.exe file

Game Version:

  • Build (4714640)
  • Platform (Steam)

Issue:

While attempting to launch the game directly from the .exe file (path: D:\Program Files (x86)\SteamLibrary\steamapps\common\AoE2DE\AoE2DE_s.exe), both with and without “execute as administrator” ways, the game fails to start.
The small launching window appears but the following message pops up: "“SteamAPI_RestartAppIfNecessary() has been triggered. Aborting startup.”, with only an “ok” choice. By pressing “ok”, the window closes and a previously hidden message appears “Fatal error: File error 12”. After closing this error message, the launching window closes automatically and I am back at the moment before clicking on the .exe file.
While attempting to start the game in any other way, only the second error message “Fatal error: File error 12” appears.
I already checked all the published solutions for these problems, but nothing works. You can trust me on this. Please have a look at my problem or contact me if you need more details!