Xcode 7 Simulator - "SpringBoard cannot be opened because of a problm."
I have had this problem and I have just managed to fix it. I am new to Xcode and only 15 years old however this fix has worked for me. 

Basically, I went to the the general page of my app and then I changed the deployment target to ios 9.2 instead of 9.3. After this, I then went to the main.storyboard page, selected the view controller and then from the standard editor, selected the option for the app to build for the deployment target (9.2).

I hope this is clear enough for you to understand and hope this helps.