I think it's Win 10 but think most of the repairs remain the same except as to the notes Shane adds for each release.
The UI is the main change from v3 but the v4 Pro version has more repair options.
Because of the changes made by MS, Shane has set the program not to do the app repairs where Win 10 is concerned.
I've had a member reporting the same black screen after the reboot in a PM to me, but he had the busy circle spinning.
I've asked him to open a new thread in this section.
Have you done a power shut down to see what it's like on the reboot ?
However, if you have a Win 10 install disk or USB can you press and hold F2 as you switch the machine on to see if that gets you into the BIOS so that you can change the boot order to boot up with the install media.
If you don't have Win 10 install media, you can create it at
https://www.microsoft.com/en-gb/software-download/windows10Read the instructions as the procedure differs for DVD and USB.
I've found that you may need to turn off fast start up to boot from a DVD and if using an UEFI BIOS then you will need to disable Secure Boot.
If you are able to get into the BIOS and the machine will boot from the install media, then click on Troubleshoot - Advanced Options - and select System Restore to see if the restore points will get you back in.
I may be able to use your experience to help the other member if he comes back.
I'll pass on your complaint as well as this is no longer an isolated event.
BTW - It may be a senior moment on my part but what is MB ?