AAA Quality First Person Arm Pack from Studios

We’re trying to get to the bottom of why you are experiencing difficulties here as we tested this exact scenario before deciding on making the rig the way we did, we tested retargeting our animations to the standard UE4 rig as well as retargeting the standard UE4 animations to our rig and there were no issues either way. I’ve created a video here showing the process without error, can you check it out and tell me if you are going about retargeting things in a different manner that would cause problems?