You could try reinstalling Poser iin a completely different location (preferably another drive if you've got it) and see if that helps. Otherwise, UVDan's suggestion is probably correct, this could well be caysed by a corrupted Poser.rsr (not to be mistaken with the .rsrfiles Poser uses for Thumbnails. Poser.rsr is a VITAL part of Poser 4 (and PPP - PoserPRoPack - not to be mistaken for the Pro Pakc for Poser 7... I REALLY Wish they would have picked another name for the "new" Pro Pack to distinguish it from the one all us oldtimers know...))

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You just can't put the words "Poserites" and "happy" in the same sentence - didn't you know that? LaurieA
  Using Poser since 2002. Currently at Version 11.1 - Win 10.