I am currently having troubles with saving and opening .pbix files. Here are some notes about the troubles I am dealing with: The message reads "Unable to save document: access to 'file path' ...
I had the exact same conversation with someone about my case.
They asked me if I was using an anti-virus software, I responded by letting them know I'm using Webroot and that my problems go away when I turn off Webroot, and I received no response to that.