Try something else before doing that...
Open up Poser and save your default scene as something - whatever you want, and close Poser.
Then open that .pz3 file in a text editor. It's just a text file after all. Remove all the references to Simon and then save it.
Then try opening that in Poser and see if you get a Simon-less, non-crashing scene.
If so, save that as your "preferred state".
Never know, it just might work, and it's a helluva lot easier than reinstalling the whole system. Besides, this is Poser's problem not your system.

I can't remember what I had to do, but I do remember that it was a problem getting rid of Simon and having Poser crash in the process all the time, but I eventually did and all was fine after that.

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