Well. something clearly went wrong. But what? Except the "Something went wrong" message I got nothing.
I was trying to activate Nintex Workflow 2013 via Internet Explorer and got up to this point.
What was wrong?
I have no idea, but I was able to activate the feature with PowerShell:
$nintex = Get-SPFeature -Identity 0561d315-d5db-4736-929e-26da142812c5
Enable-SPFeature $nintex -URL "THEURL" -Force
How did I get the ID for this feature?
Get-SPFeature | select ID, DisplayName, Scope | Export-Csv C:\FeatureList.csv With this list, you can get every ID and just activate them with PowerShell.