I stumbled across this by accident while rendering my Father's Day piece. I mass-activated motion blur for all layers in my final comp, then sent the editor timeline (containing my comp) to the export queue. When starting the render, though, it immediately halted with an error:
GL_INVALID_OPERATION - The specified operation is not allowed in the current state.
The offending command is ignored and has no other side effect than to set the error flag.
After a little trial and error, I found that the problem was activating motion blur on a grade layer in my comp. I just tested the following sequence, and it successfully duplicates the error:
This is all happening in HitFilm Express 2017 version 5.0.0094 (Update 6)
Mac Mini (Late 2014)
Mac OS X 10.10.5
2.6 GHz Intel Core i5
8 GB 1600 MHz DDR3
Intel Iris 1536 MB