Apple is creating a cache of the UI layout and it's corrupted. This affects quite a few applications. You'll need to delete that cache but it's in a hidden folder.

• Open Finder
  
• From top menu choose Go > Go to Folder ...
• Type or copy n' paste this:
• ~/Library/Saved Application State/com.Bondware.Poser.savedState
• Delete the entire contents of that folder:
  • data.data
  • window_1.data
  • windows.plist
    
• Launch Poser.