Stack is empty error in 3.3.0 on CB3.1 UR5

We are getting the following error during runtime on a UR5 running 3.3.0 software, since the error says its an unknown error we have no idea where to even look. It is a random error, occurs at random times during program execution. @jbm any ideas? I will upgrade the robot tomorrow up to 3.3.3 that we just received notice of today since I am seeing some other bugs that I know are fixed now.

Hi Matt

I will report this unknown error as a bug.
Please send me a program and installation to reproduce this: support.urcaps@universal-robots.com