An update to this:
This issue still pops up every now and then and has started showing up in other team members work. I can say for certain that saving as an IDML does not help, restarting InDesign does not help, re-installing in5 does not help. I can also confirm its not an issue with the file, as the team member seeing the problem sent me the file and i had no issue, after saving it and sending it back they still have an issue, which to reiterate persists to any other document including newly created ones.
I was able to get mine to work once by clearing my preferences (pressing CMD + Option + Control + Shift right after clicking the icon to boot up InDesign) but this did not help the other team member who had this issue.
What DID work for him, was removing the data.ajlf file found in Library > Application Support > Ajar Productions > in5. doing so will require the user to re-activate their license, but after doing so the resources plus buttons work again. This seems to indicate the problem lies with in5, but since i can't figure out what triggers the problem to begin with, its been really difficult to diagnose, and i can't imagine Ajar's support team will be able to do much without being able to replicate the issue.