Did you allow the car to reset? Are you getting an SOS warning on the dash display or iDrive? If you get the SOS your optical connection is not correct. If it is connected properly, do you have a 12v out from the blue remote wire?
Mobridge DA2 > JBL MS-8 > JL Audio HD600/4 > (3) Hybrid Audio L3SE & (2) Rainbow Cal25; JL Audio HD900/5 > (2) Morel HCW-10 & (1) IDMax 15