I've been signing compiled apps for several months and have a script that calls the Windows 10 SDK signtool. It's been working fine on two different computers and my certificate is valid. Today, I just started getting an "Unexpected internal error" with the error number listed above. I tried disabling antivirus which helped in this case but not mine.
My app is written in Delphi but I don't think that matters as this same problem was reported on Microsoft's Developer Community under Visual Studio. I had been using version 10.0.18362.0 of the SDK but after getting this error, found there's an update and tried version 10.0.19041.0 but got the same error.
Anyone else with this problem? Any suggestions?