I had this problem.
Car wouldnt go in to manual mode, was hard changing between D, N, R etc and sometimes lost all power as if it was in N with all the SDNRP flashing red.
It was the gear selector, cost £450ish i believe to get it sorted.
It wasnt the actual DSG box, just the gear selector module! I can give you the details of who sorted mine out if you are local to Bromley in Kent!