Let me know if I can give any additional information, currently using unreal 5.3
Did you ever find a resolution to this? I’m experiencing a similar error, can’t get the control rig to compile because it claims there are several arrays “out of bounds”
For anyone curious about this in the future, just make sure you initialize the array with the maximum number of indices you use in the default value. I was manually setting the length of the array in a loop under the Forward Solve event, but it only stopped giving me a compile error after I added 6 blank values as default.

