Unfortunately you haven't given much detail. Which OS? RAM? CPU ? Graphics card?
If you are on a Mac, run a Disk Permissions Repair of the Boot drive and try again.
let tag on to problem.
I am experiencing constant crash..
Imac , os x 10.9.5 intel core i5, grfx Intel iris pro 1536 , 16 ram
creating 12 sec multiple layers (9 video tx) of just stills ..with moves etc.. but setting keyframes and moving image is delaying... and ..crash shutdown.
also after rendering , sometime no video at all ...or will freeze on a frame as audio and time line continues... or not play at all.
and... sometimes after re start.. , again , no video...as audio plays on.
Have you repaired disc permissions?
FYI: Intel Iris won't give you an optimum performance.
Also, if you would paste the error log of the crash, that would be helpful. I would suggest going through this: http://blogs.adobe.com/kevinmonahan/2014/09/10/premiere-pro-cc-freezing-on-startup-or-cras hing-while-working-mac-os-x-10-9-and-later/
How large in frame size are the still images? If too large, resize the photos in Photoshop to a smaller size and try again.