Have all of the following installed.
.NET Core 3.1 Desktop Runtime x86 Link
.NET Core 3.1 Desktop Runtime x64 Link
.NET Core Current Runtime x86 Link
.NET Core Current Runtime x64 Link
.NET Framework (get latest) Link
(Both x86 and x64 of the .Net Core MUST be installed)
Reboot PC when done.
thanks, great, was banging my head to same problem: old trainers work, newest won't. trainer launches and crashes/disappears after authenticating user. this fixed it