Rhino.Inside - Grasshopper components throwing exceptions: "object reference not set to an instance..."

Hi -

I am opening a previously perfectly functional grasshopper definition in Rhino Inside Revit and all the components suddenly fail and give the exception “Object reference not set to an instance of an object.” This only happens with a very large Revit model that is hosted on an external server. When I open the Revit sample test model the grasshopper definition works fine and does not throw this error. I have recently updated both Rhino 7 and Rhino.Inside.Revit. Am dead in the water with this issue - any ideas how to fix it?
Thanks
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