I have this bikini and I have just tried opening it in DS 4.5. It opens fine without spikes. I downloaded a new copy from my account here and it worked fine for me.

I tried a variety of things on it. Converted to SubD fine, Triangulated  fine, Applied Smoothing  fine. I treid most of the morphs and they work as expected. I was not able to get spikes or any strange effects. This is with the bikini loaded into the runtime folder, within the DS content library.

If the people with problems could describe exactly how they are loading it I would be happy to try to replicate the problem. Failing that, perhaps one of them could export the spikey object and email it to you, so you can see what has changed?

 

Cheers

Ian