Please make sure that your wplms theme and all its plugins are updated to latest .Resave permalinks and clear browser cache .
If none is working then try enabling the " Revert pretty permalinks for Courses " from wp-admin-> lms -> settings .
Also note that there is an issue with the custom course permalink.
If you have changed the course permalink (refer :
http://prntscr.com/9zb4z2) then the endpoints wont work .
Please try setting the course permalink to default .
refer :
http://prntscr.com/9zb5n5
Fix for this is coming up in the update of vibe course module plugin which is releasing more or less tomorrow .