Please make sure you have the following
.NET Framework Runtime 4.7.2 or above: dotnet.microsoft.com/download/dotnet-framework
.NET Core Runtime 3.1 or above: dotnet.microsoft.com/download/dotnet-core/current/runtime
also try to repair if already installed.
after that restart your pc.
Yep, tried to repair after I got the message. Trainer was working just fine before Aug 7 which was the date I let 2004 through having not done an update since late June. KBS4562899 installed after which was a NET 3.1 update from late July related to optimizations for the 2004 update.
[Edited by jmike00, 8/11/2020 6:46:32 AM]
Re-install *BOTH*, then reboot, then try the trainer. Should be good to go.