I have no field marshals.

[unmerged(36289)]

To keep it simple: I have no field marshalls. They are not there. I don't know why.

 

[unmerged(15485)]

Then just promote somebody.

 

[Castellon]

I doubt this is technical related.
Reinstall, if that does not work post in the general forum, to see what is up, maybe it is WAD for your nation.
If it is a bug follow th eprocedures outlined in the sticky thread on the subject.