Had a curious issue recently where I had set up a new Dynamics 365 Version 9 on premise server for testing. Everything was working as expected until I upgraded to the latest September 2019 release of CRM (update 0.8).
Upon further examination though, it had nothing to do with the update, it was the new Organisation I had created called “Portal”. For some reason, this organisation simply would not work, giving an error when trying to access it. I could see some nasty error messages in the Event Log which made me think it was something to do with the Upgrade (Assembly DLL load issues).
However, I created a new Organisation which actually worked fine.
I think I have come to the conclusion that the name of the org, Portal was producing some internal error with CRM and preventing it from loading. Maybe /Portal in the URL is reserved for something else, who knows.
Its not something that would probably affect many people, but I felt compelled to write a post about it in case anyone else was stuck with this.