error dependency

Checks for rigid elements that share dependent nodes with other rigid elements.

See - 

HyperWorks Desktop Applications > HyperMesh > User's Guide > Browsers > Model Checker:

OptiStruct 

Go to rigids > update sub-panel > check connectivity option > select the element whose double dependency you wish to remove, click on update > unselect the double dependent nodes and click on update.

Hi, I am trying to make my double dependent rigids, non-double dependent, but when I select my double dependent node (by left mouse button clicking it I presume) and then click update, it just automatically unselects it and nothing happens. I'm struck dumb with this problem and haven't been able to solve it for the past 3 days. Any suggestions would be more than welcome!