At the Moment there is a problem with the new version of Krita and the actual drivers for UGEE tablets. We informed the developer of both and try to get a solution for this problems. But at the moment you can solve it by installing an older version of Krita. Sadly the developers of Krita don’t own a UGEE tablet, but we try to get in connection and try to help.
For using Krita and UGEE wihout these huge problems, please install Version 2.9.11 of Krita.
Link for installation (32 bit): https://files.kde.org/krita/windows/krita_x86_188.8.131.52.msi
Link for installation (64 bit): https://files.kde.org/krita/windows/krita_x64_184.108.40.206.msi
And if you are looking for the Kritabrushes, I often recommend, you can find them there.
The newest UGEE drivers: http://ugee.net/download/index/id/65.html