I encountered the "unspecified error" while trying to unpack the MHI Character pack for Hero Designer, after a bit of frustrated searching discovered that the Windows 10 default compressed file management doesn't deal well with the compression format the charpacks use. I downloaded 7-zip, extracted the files where I wanted them with no issues.
Only posting on here because I never found (easily anyway) anyone else's experience that talked about that.
KarlGump got a reaction from sentry0 in Encountered "unspecified error" when extracting charpacks
