Error: Object reference not set to an instance of an object at Diamonds.TLoads.GetNumberOfLoadGroup()

On opening a model, you get the error:

Solution 1

• Remove all load groups. Test if the error is gone.

Solution 2

• Export the model to BIM Expert.
• In BIM Expert, make an export to *.bsf.
• Open the *.bsf again in Diamonds. Test is the error is gone.