AE cs6 render error

I am trying to render my video as a quicktime format, i set it off rendering and after 2 hours and 16 mins it stops and pops up with the following error:

i have tried rendering 4 times after each time restarting after effects and my computer but it still stops and displays this error at roughly the same point during rendering

these are the render settings im using:

any help would be great and if you have had this problem and found a solution i would love to know.

if you need any more info let me know.

Thanks