A flaw in the Windows update causes these issues. It seems not all computers are affected, so it seems just bad luck. I’m sure Microsoft will release another update that will fix the issue.
We’ve helped other customers with this issue, and as far as I know the problem is solved.
What you could try is the following:
- Start MainType
- Create a group (virtual folder) named “Installed Fonts”
- Select all installed fonts
- Copy them to the new group
- Uninstall them all
- Reboot your computer
- Start MainType
- Select the group “Installed Fonts”
- Install all fonts within the group
Please be aware this is not something we recommend for normal situations, so use this information at your own risk.