Glad you got it Ulco.
I have seen similar problem before. In my case, it was that I had way too high settings on my brushes, and I was using those brushes on an uneven surface (not exactly perfect quads). So when I applied a brush the surface exploded. IN appearance, it looked pretty much exactly like your example image.
But I don't recall ever importing an object and getting the explosion right off the bat.
Anyway, I guess you know how to avoid your specific issue from now on?
...
I remember this bird. You made that a wile ago, no? re doing it now? or just making some changes?
The OP image looks like the beginning of the formation of the "TEserack" from the film "interstellar".