This issue has been brought to our attention and resolved. If you are having issues with Module List links not working or disappearing, please reload the course and see if the issue is still happening. If the problem persists, please send us a support ticket with the HTML from that page.
Just as a little background on the issue, the October release
that was pushed yesterday included some user-requested updates to the module list functionality. One of those requests was to make it so that unpublished modules did not appear for students until the module was published. The problem is that the code looked through all of the modules in Canvas and flagged each module link in the list that the student can access and then removed modules that they cannot access. What we did not anticipate is that people would change where the links point or add links to the module list that do not point to a module. This has now been resolved.