DMIG

I would like to use condensation to calculate the normal modes of
a structure. These grids are connected to the structure through RBE3 (master
grid). Let me know if there's a way to use the master grids of RBE3 elements in
the A-SET?

the error form the f06  

*** USER FATAL MESSAGE 2101 (GP4)

GRID
POINT    1000005 COMPONENT  1 ILLEGALLY DEFINED IN SETS  
UM   UC 

can i include mechanisms while creating DMIG in FEA?