SourcetreeEnterprise: CompositionException after updating from 2.6.10 to 3.0.8

After updating Sourcetree Enterprise from 2.6.10 to 3.0.8 Sourcetree doesnt start anymore. The splash screen is shown, but then nothing happens.

The log in C:\Users\user\AppData\Local\Atlassian\SourceTree\sourcetree.log says:

2018-11-06T11:47:32: CompositionException [Errors occurred during discovery.]

I tried to deinstall sourcetree before installing by running:

$sourcetreeGUID = (Get-WmiObject -Class Win32_Product -ComputerName . -Filter "Name='Microsoft .NET Framework 2.0'").IdentifyingNumberStart-Process -Wait -FilePath C:\windows\system32\msiexec.exe -ArgumentList '/x', $sourcetreeGUID, '/qn'

But that doesn't fix the issue either.

After completely removing everything related to sourcetree and performing a new install, Sourcetree 3.0.8 does start. I think this is unwanted, because users lose their preferences.

This is the case for all 3.x versions so far and possible for versions 2.x as well.