Alrighty
spent a day figuring this one out.
At some point within the past 3 or 4 versions of Playmaker I believe my global variables got corrupted. I specifically remember it happening around the time categories became a thing.
The issue was that when making a new global variable, it would delete one that was made prior, unlinking it from anything that was referencing it.
Here's what I did to fix it:
1. Open up your PlayMakerGlobals.asset file in mono.
2. Go to the variable header of the type of variable that was deleted. For instance, mine was a gameobject, so I scrolled to here ->
3. Go through line by line and see if you have any duplicate variables. It would look something like this ->
4. Delete BOTH variables sections. I've highlighted what it should look like in red.
5. Save the file. Exit out of the Global Variables window if you have that open. Then close Unity.
6. Open Unity again, open the PlayMakerGlobals.asset file again and do a ctrl+f to search for the variable to make sure it's not in there.
7. Open your globals variables window, create the variable again.
8. Go through your Error Check window and go ahead and put in that new variable you created.
***If your variables keep appearing in the PlayMakerGlobals asset file even after you delete them, delete them again, and delete all your categories from the file. Just scroll down til you find the area between Global Variables and Events. Or do a quick search ctrl+f for 'category'. Delete all the dashed categories and the category ID's (but be sure to leave a single dash under categories). Make it look like this ->
After that, close Unity, open it back up and you should be all good to go!
I hope no one else has to put up with this problem. Cheers to a bug-free PlayMaker 2.0!
-craigz