@girish Will do. It's actually not the first time I've run into the problem and a re-fresh of the API credentials solved the problem, although this is the first time I specifically observed that it was a 500 error vs. a 401.
@alex-adestech And the web app requires mongodb? I am wondering why you want mongo username and password. But as @murgero pointed out, please create a new thread and we will help you out.