Bug/error preventing robot from running program

Since updating our UR3e robots to 5.10, one of them has been experiencing the following issue:

This error appears seemingly at random, prevents the robot from starting its program, and the only way to fix it is to reload the exact same program from backup. I’m assuming there is something syntax related that changed from 5.9 to 5.10, but I am not sure exactly where to look. Any help would be greatly appreciated!

It would be difficult for anyone to know why this would be happening without seeing more details of your installation and program. I recommend you reach out to UR service at myUR where you will be able to upload files for evaluation.