I am using the Add User to AD Group control and it works fine in terms of adding the user to a group. In order to capture errors, specificly if the user is already a member of the group, I enabled error handling (Capture Error = YES) and stored the error in a variable.
However it does not always work. I can run the workflow several times knowing that the user is already a member, and I capture nothing. However, sometimes I do capture an error, and once I do so, it keeps getting caught consistantly.
My only thought is that its querying different Domain Controllers perhaps??
This Sharepoint 2013, Nintext 2013 on a Site workflow linked to a start form.