I'm now just learning purchased WPLMS using sample data. The problem is that student doesn't see any button to mark unit as completed, and I couldn't find the place to set it on.
Can you please check these settings in wp admin->WPLMS->course manager :
http://prntscr.com/8y2duj
It should be marked as shown in screenshot.
Let us know if this helps.
I have marked settings as shown but it doesn't help. Now I guess that my page with course description differs from what it should be. I never seen the screenshot as shown on FEATURES -> FEATURES COURSES -> FEATURES COURSE STRUCTURE in the sample data menu.
Can you please share your site url as well as admin credentials to check the issue on your setup.
Make sure to mark the reply as private when sharing site credentials.
Everything resolved when I fully reinstalled WPLMS. As I guess, it was a result of errors during some plugins updating.
Thank you!