hmm, come to a point where my statement is not 100% correct.
One Applications is fixed by modifiying UviProcessExcludes, however thats not my main issue.
Previous RDS Servers were 2012R2. I found out, that when running these applications on 2019 the Application Error 1000 Kernelbase.dll does not come up when users have Write Access to %ProgramFiles%\Application Path (which is a no go).
I think this are just crappy apps, however does anyone know if there were major security changes 2012R2 => 2019 that would result in this appcrash?