mystery loss of 2 OHQ

[Poliorcetes]

So my OHQ both are suddenly gone this turn. I don't see any notices about their loss, their troops are suddenly in my SHQ reserves.
This is so frustrating in a game that is full of tiny details and innumerable reports. But there is no combat summary or history (though I don't see an enemy that was near them) to review. But my entire command staff just disappears and nothing in the game will tell me why . . .
The lack of combat history is a separate complaint unless you sit through the AI portion of the turn and keep an eye out for the attacks, you won't have any idea where combat is occurring in your empire.

[demiare]

Reasons for them to disappear:
1) You forget to feed them and they starved to dead. Either because of lack of logistic points near them or because your empire lacking food / they'd been cut from your SHQ.
2) You changed quality level of model they'd used so they're prohibited to use it. Example: make your only type of infantry obsolete -> OHQ will send every infantry back in SHQ as obsolete one -> next turn it's disbanded as it no longer contain any units.
3) You hit button "disband". Silly reason, but ... [:D]

You can replay combat results of enemy attacking your soldiers using "HIS" HUD option (top-left part of game screen).

[zgrssd]

ORIGINAL: demiare

Reasons for them to disappear:
1) You forget to feed them and they starved to dead. Either because of lack of logistic points near them or because your empire lacking food / they'd been cut from your SHQ.
2) You changed quality level of model they'd used so they're prohibited to use it. Example: make your only type of infantry obsolete -> OHQ will send every infantry back in SHQ as obsolete one -> next turn it's disbanded as it no longer contain any units.
3) You hit button "disband". Silly reason, but ... [:D]

You can replay combat results of enemy attacking your soldiers using "HIS" HUD option (top-left part of game screen).

1 is unlikely, as loosing the OHQ does not disband the subunits
2+3 seem rather likely. As they do affect the subunits as well as teh OHQ
2 in particular keeps happening, because people select Obsolete withotu first reading what it means...

[gmsitton]

It's happened to me. In the cases I looked at, the OHQ was at the far end of a long supply chain. I assumed they decayed due to lack of supply and/or were attacked and easily killed due to low supply. It pays to check the missing units and missing HQ tabs under Raise Formations as part of your management each turn.