I was just watching a video Ehsan did about pyRevit 4.7.6 & Routes Framework and noticed that he mentioned this error. The error messages are actually intentional:
Don’t worry about these errors and messages and stuff that you are seeing. If you have the pyrevit developer extension enabled, these error messages are intentional. They actually do test and make sure that pyrevit will show an error message where it needs to show.
Not sure about the error @GooseG posted. I think that is a separate issue, not something with routes. I’m guessing it has been fixed in recent versions of pyRevit.