Hi Magnus, I'll be able to check it out better when you send the file, but one other thing you can try is to save it from Rhino as a Rhino V3 file.

MoI uses the Rhino V3 library to read .3dm files - normally V4 files are also readable, but maybe it has something to do with some change in the V4 format for blocks or block definitions or something like that.

I should be able to pinpoint it better with the actual file example...

Thanks,

- Michael