I have the same problem with quiz questions as described in this posting from two months ago: https://wplms.io/support/forums/topic/cannot-assign-questions-to-quizzes/
I have tried both the No and the Yes options in WPLMS > Course Manager > Enable Linking, but I only get what you can see in the attached screen shot. When I click the blue "Add More" button by "Quiz Questions" it just pops me back to the top of the page. Also, the On/Off sliders for Auto-Evaluate Results, Dynamic Quiz, and Randomize Quiz Questions don't work.
Using WordPress 4.3.1
Okay please make sure that your wplms theme and all its plugins are updated to latest version .
Check js errors in your site .
https://codex.wordpress.org/Using_Your_Browser_to_Diagnose_JavaScript_Errors
If there is any then please try deactivating the third party plugins for this .
We purchased the theme in late Feb. 2015. If I go to themeforest.net and log into my account do I get to download the latest version, or do I have to pay again?
Yes it would be available for download with your themeforest account .
If the latest version is available, then you're going to have to be a little more specific as to how I actually get it.
Here's what I'm doing: I go to my themeforest.net account, and go to the "Downloads" section and get the .zip file and extract the package. Currently my WPLMS installation says that I'm using version 1.9.1 of the Vibe and WPLMS plugins. When I go to the extracted package and look at the changelog.txt of the plugins, it says version 1.9.9 at the top. That looks promising, except that when I go to my WP dashboard, deactivate the current plugin, delete the folder from my server, copy over the supposedly new version 1.9.9 of the plugin, and re-activate the plugin, my dashboard still says that I'm using version 1.9.1 and that version 1.9.9 is available. And yes, I cleared cache on my browser.
I sent a message today to the Help Center at envato.com about getting the latest version but their response time is listed at 4 days. Anyway, I not even confident that what is supposedly the latest version really is the latest, given my experience so far.
Disregard previous reply. Issue is resolved.