Britglider, how are you?, well i had the same problem and contacted ED about it; they tried to help me, but nothing was fixed, they tried though.
The reason is your water, when the water is set higher than "Medium" AND the clouds are set to 8 or higher it will crash to the desktop. It took me awhile to figure it out, but now i donj't have the problem anymore, just medium water. Just set your water to medium and you'll never have the problem again. Hope this helps :D