Why am I not authorised to access my server?

I opened up Plex today on my laptop to add some new shows to my library but I’m getting a notification saying I don’t have access to the server. I’ve not changed my password, I only have one account and I followed the instructions on the support article, and I still can’t access it on any of my devices.

I have now deleted the server but am unable to open plex media server to readd the server