A number of draw.io users are encountering the message "Error Loading File.Daily Limit for Unauthenticated Use Exceeded. Continued use requires signup." when trying to open draw.io files from drive.google.com.
To workaround this issue go to https://www.draw.io/?mode=google and open your diagram by clicking the open button and select the file.
UPDATE : We have found a workaround for the problem. If you clear your browser cache for the draw.io domain you should find it working.