I often use split to cut tall parts into layers so I can machine the layers and then glue them back together.  I have just had a problem in 2 parts I have done this to.   The derived parts are there but I want the original part split into multiple bodies.  The screen is blank and there are no bodies in the design tree.  

I have done this hundreds of times and never had this problem before.  I did recently update to 2015 but I did this a few days ago and had no problem.

Does anyone have a solution apart from creating an assembly from the parts?