Hah yeah, This is the police (1) and the appropriate trainer
Weird, not sure what to do. Yes, this is the only trainer with the issue. I have several others that work fine and just double checked them. It happens when I activate the trainer (F1), it says "Please wait" and then a few seconds later "Error"
I tried the .NET link, when I open that it's a repair tool of sorts that says it's fixed any errors and to try installing .NET again - I do that and it says it's already installed and won't go any further.
I'm running the checks now on my system (Windows 10 Pro 64)
I have one other by 0x90 that works fine for Frostpunk.