I'm far from an expert and have only been working with Daz about a year and a half..but I would check the render settings first.
If you were locking up with V 4.2 you aren't the only one so you may want to check the forum at Daz..there was a discussion going on there with one of the techs.  She locked me up too when I first loaded her..I even lost the whole scene file I had made...poof and it was gone.  The next time I loaded her I checked each item as I placed it in the scene..so far, so good.

Good luck...but do check out the Daz thread too.

 

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