Inaccurate render mesh

I just started having problems with render display mode mesh accuracy. See the attached example. Render mesh is way off from the actual model geometry. What setting might I have accidentally changed?

Hello - is the model very far from the world origin?


383 kilometers. The model is registered to a local county topographic map so way off 0,0

Ok, will try that then, thanks! I have been working on this model for some months with no problem. would it break all of a sudden like this based on distance from 0,0?