Your comments

Yes. I tried those. I used a third one and it works. Might be one of my multiple add-ons blocking something. 

Having seen it at work, I have an immediate suggestion. The tool searches for author names, which is not very useful since author names are similar across and within fields. That was the case for me. I suggest instead using usernames, which by definition must be unique within the system. 

So, rather than using

I would strongly suggest using