Solidworks locks up when clicking on part

I need some major help; I have an assembly that I have
created a part within the context of the assembly, now every time Iclick on this part
either in the viewport or the feature tree, it locks up SW. I candelete the features/mates in the part but that is all I can do. Icreate these internal parts all the time, the only thing I diddifferent was I imported an assembly that has faces and models,then I created the internal part. I have deleted the imported file.

Is there another way to extract this file from my assembly?

any help would be greatly appreciated

Frank
SolidworksAssemblies