I have installed the WPLMS Co-Author Add-On and am not able to see or edit the author meta. Even before I installed this plug-in, I am not able to see author meta when editing a course, which is absolutely essential and I am on a very close deadline.
I have attempted disabled and re-enabling plugins with no avail. I have also tried adding some of the code provided on other topics (then removing as instructed) with no success.
Please make sure you have installed the co-authors plus plugin along with the wplms co-authors plus addon plugin.
Also check if you have enabled the author options from the screen options present at top right side of the page (while editing the course or pages).
Let me know if this helps.