Hi,
I'm having similar problem. I can access the project site myself but students cannot access the project (which is public) with similar "Failed to map image" error message.
Although I receive the same error regardless of a project -- simply opening up a new untitled project will produce the same task error. The most recent new untitled project producing this error: https://rstudio.cloud/project/128839
Thanks for reporting these issues, and apologies for the trouble!
We've discovered an issue with a subset of volumes which prevented new and copied projects from being properly initialized. The issue appears to be rectified, but we are monitoring for re-occurrences.
Projects that fit this criteria are those which are unable to be opened and were created between 7:30a and 10:30a EST today, 11/6. You can safely delete these projects as they were never able to be properly opened (so no unique data will be found in them) and they will never be able to be opened.