We started getting an error “We did not run this pipeline because the project has no follower with access to the repo.” but I can’t find documentation on how to fix it and we haven’t made any recent changes. Please help 
I’m having the same issue with a build pipeline that hasn’t been in use for a few months.
Got it working by editing my webhooks in github for the project and sending a “ping”. Then I pushed a new tag to start a new build and everything worked.