sometimes the modal functions don't run but there are no errors displayed when you check the model. one way to find the problem is to set the run on SAPfire solver then run the model... after the model is run there is a text file generated..
you can find the joints or lines causing the error in this text file...
the problem is that the label of the joints is usually wrong .. but the coordinates of the joints are written .. so i wanted to know if there is a way to select a joint by coordinates just to make it easier finding the joint ..