I got a FATAL after an attempt at running a model.
I ran a static model, modified the .DAT file for buckling, added statsubs and method to all the subcases; added the EIGRL card, created a new constraint group (fixing all 6dof) and used the group to create ASET bdf.
Is fixing the 6dof appropriate? If yes, what could be source of the singularity FATAL I am getting?
Why are you manually modifying the DAT file?
From what I recall from using FEMAP years ago, you can launch a Nastran Sol 105 buckling analysis from within FEMAP, the same way a static SOL 101 is launched.
And you should not need to change the boundary conditions.
I would try to sort out the analysis procedure using one load case with a simple loading before trying to do it with multiple load cases, etc.
Have you plotted the static analysis displacement results? is the displacement appropriate/reasonable/expected? Can you plot some images here?
Yes, posting in the FEMAP or FEA forums (not both) may get you more help.