MRTK 2.2 - Cant build because of error while creating certification

[Mt-Perazim]

I updated to Mrtk from 2.1 to 2.2 and Unity from 2019.2.15 to 2019.3. In play-mode everything works fine but my build is failing because of following lines:

#1
Failed to create a file 'MRTK v2.0\SomeApp Mrtk 2.2\Assets\WSATestCertificate.pfx' 
UnityEditor.EditorUtility:WSACreateTestCertificate(String, String, String, Boolean)

#2
Error while creating certificate at 'MRTK v2.0\SomeApp Mrtk 2.2\Assets\WSATestCertificate.pfx'
UnityEditor.EditorUtility:WSACreateTestCertificate(String, String, String, Boolean)

#3
InvalidOperationException: Failed to create test certificate.
PostProcessWinRT.CreateTestCertificate () (at C:/buildslave/unity/build/PlatformDependent/MetroPlayer/Extensions/Managed/PostProcessWinRT.cs:1045)

I tried to delete my old WSATestCertificate.pfx and switched my build folder, but that didnt help. Is sb else experiencing the same behaviour?

[Mt-Perazim]

I somehow "fixed" the problem, by downgrading Unity back to 2019.2.15 and updating again to 2019.3. Or by resetting my build and project settings in unity. The only part that does not look good are the 147 Warnings about obsolete api...but my building works now and the app runs!