I dont know if this helps but I started to have a problem whit halo 4 couple of days ago. it would not simply connect to halo 4 servers alltough my network connection was fine. Ny I tried to do new trial account whit trial time i got whit halo 4 and amazingly it worked so could it be that some one else suffers same kind of problemand could this solve other problems too?
PS. Itried my old account whit mass effect 3 but it worked perfectly.