Max number of SU HQs?

[Esslingen_slith]

I am at Nov. 42 (mud) as Russian a russian player.

I have enough Admin points but I can not build any more Rifle or Tank HQs.

Is there a max. number of HQs?
Can I disband a Rifle HQ to build up than a new Tank HQ?

[gingerbread]

Are you building in an eligible hex per 18.1.2?

[Esslingen_slith]

ORIGINAL: gingerbread

Are you building in an eligible hex per 18.1.2?

Yes, I made several in the past. I tried for example at Saratov or Stalingrad.
I could made the last HQ before the new Front at November42 arrived

[Esslingen_slith]

It is again all fine now!

In the first snow turn I can now make my 5th tank army headquarter again.

Probably I have done some sort of mistake the last turns. I could not find out what but now it is all the way it has to be again.