I have had this happen to me as well. the work around i use if your work on a Mac with OSX is this...
- go to your Apps folder and find the Bryce5 folder and open it to find bryce5 icon
- press command I
- click (open in classic) and close window
- start up bryce5 and import your poser obj object
it will open then.
5.after you import the file save it, quit bryce and repeat step 1.
- uncheck (open in classic) then you can start working with your new bryce file in OSX.