Issue with trying to read playerex attribute values?

[DigitalVaporeon]

So, I'm trying to make a datapack for the Origins mod that utilizes PlayerEx in order to lock origins behind PlayerEx levels. Origins has the ability to execute a command when a condition is met, and is able to check vanilla MC player attributes for this purpose just fine. When I tried to use it to check the "playerex:level" attribute (which I assume tracks the player's playerex level?) it causes an "Invalid Player Data" error and boots me out of the world. I'm not certain if this is an Origins issue or a PlayerEx issue, or me simply misunderstanding the documentation? Any help would be appreciated.