Hello! You have two options:

* either run GTR2.exe and GTR2Config.exe in Windows XP compatibility mode and as administrator

* or, have a look at Crew Chief GTR2 Enhancements Plugin. Plugin fixes bunch of things in Steam GTR2.exe, including startup issues https://thecrewchief.org/showthread.php?2012-Crew- Chief-GTR2-Enhancements-Plugin-Setup-Instructions- Known-Issues-and-Changelog In order to fix startup problems you just need to copy 2 plugin files, but plugin adds bunch of optional things, soon 70 pages of features and fixes and I am not done yet.

HTH!

PS: just realized this is German section, hope it's ok to post.