I’m having a similar problem to what others have reported. When I try to transfer a bootcamp partition using Winclone 8 from a Late 2014 Mac mini to a Late 2018 Mac mini I get the error message saying it couldn’t mount the EFI partition. I’ve seen references to AV programs causing a problem. I have no AV program on the Mac side, but the backup I’m trying to restore does contain a WebRoot AV. It was not clear to me if the issue with AV software causing problems was on the host Mac or within the Bootcamp partition being restored. It would seem unlikely that an AV program within the Bootcamp partition would be the problem, but I want to ask to make sure.
I should mention that I was not able use Sysprep, because I got a message saying that this was an upgrade version of Windoze. This has been reported by others.
Both old and new Mac are running Catalina with all updates. The bootcamp partition is Win10-64.
Also, any other suggestions about how to tackle this problem would be appreciated. I did try to issue the terminal command suggested by some (sudo diskutil mount disk0s4) and got the response: “Volume on disk0s4 failed to mount.”
This has been quite frustrating, as I’ve successfully used Winclone before without any problem. I’m almost to the point where I’m going to just create brand-new bootcamp partition and a new installation of Windoze and reinstall all of my software. I would seemingly take less time as I’ve been working at this now for two days.
Any and all suggestions are appreciated. Thanks.