i realize this will be fixed in the next hotfix per thread discussion, but for those that need to upload immediately for various time constraints, there is a great tool called ‘iReSign’ which is free and on github. that allowed me to package everything on the pc with UE4, and then just run that ‘iReSign’ script on the mac before uploading the binary. upload and submission through itunes connect was successful after that minor extra step. this is also in accordance with initial answer of ‘sign on mac works fine’ but i’m somewhat useless when it comes to mac os, so this script was really helpful.