I support teachers and students with their use of Canvas. Most questions are easy to answer because people ask me how to do something. There is a lot of information online.
Sometimes people contact me because something is not working. A file is not uploading is the most common problem (in assignments, documents, Arc,...).
Most of the time I can solve the problem by recommending a different browser. It would be nice to create a list of these problems and the solutions that solved them.
Honestly 99.9% of our problems like this relate to IE/Edge. Our policy is to strongly recommend that students and faculty use updated versions of Firefox or Chrome.
In most cases if there is an issue with Firefox or Chrome it seems like updating, clearing the cache, or switching to the other browser (Chrome to Firefox or Firefox to Chrome) fixes the issue.