''locking as a dupe of https://support.mozilla.org/en-US/questions/1059357'' hello i upgrade my firefox from 36 to 37.0.2 on ubuntu 64-bit OS. after i upgrade my firefox i can't run my both profile at the same time. at the first i run firefox, in the dialbox my both profiles are shown but when i select one profile and run it, if i want to run the other profile at the same time the dialbox is empty!!!