Comment 2 for bug 1254256

I had the same problem and I solved as follows :
The problem : when I open the terminal, it shows "There Was An Error Creating The Child Process For This Terminal'
text was empty or contained only white spaces" with two red boxes in the upper corner containing text "profile preference" and "relaunch"
To solve the problem : Click the profile preferences box, untick "run a custom command". Exit. Close the terminal and relaunch. Thats it.