I browse to open an assemnly and I see a preview of it. I then open the assembly and all I see in the design tree is the sensors and annotations folder. All part information and the model itself is gone. When I check the the assembly references they are missing so it appears the assembly has somehow lost these yet when I requested the file to be sent to me, the user used Pack & Go from the assembly to send me the files. Since Pack & Go worked there must be some links intact.

Is there anyway to recover this assembly other than starting from scratch again? If not then can someone explain how files may become corrupted other than SolidWorks crashing?