Hi and happy new year!
This morning I wanted to update to the latest version of coursepress. The update finished successfully - yet after finishing, all units in courses that were not already published went were missing.
I rolled back the site via the Snapshots plugin so that I wouldn't lose too much work. But this is a critical problem and should be fixed!
PS: Further information/details - I also updated a few other plugins including Marketpress, if that is related to the issue.