Got a new Poser 12, and lots of Poser 11 files. When I open a poser 11 file, three things may happen:

1 I get an error message that says "this file was created by a previous version of Poser. Poser will attempt to import it". sometimes it can open the file after  a few minutes thinking, or may just crash.

2 immediately crash, no warning message. As soon as I click on the file to open it, a spinning colorful ball appears and poser is totally paralyzed.

3 the 11's file opens as usual, like any other poser file. I can male any change I like, save the file, and next time I open it, it is perfectly normal.

Any idea why some files open as usual, and why others cause poser to crash?, but more important, how can I solve this? (I've got tons of older poser 11 files).