High command seems to have stopped working completely on dev branch. When you press Ctrl+Space nothing happens.
I think there were reports that it doesn't work on perf branch either.
Test script: (it should enable you to use Ctrl+Space; no need to have any groups besides the player group)
if (synchronizedObjects player findIf {typeOf _x == "HighCommand"} == -1) then {
_group = createGroup sideLogic;
_HighCommand = _group createUnit ["HighCommand", [0, 0, 0], [], 0, "NONE"];
_HighCommandSubordinate = _group createUnit ["HighCommandSubordinate", [0, 0, 0], [], 0, "NONE"];
_HighCommand synchronizeObjectsAdd [_HighCommandSubordinate, player];
};
_group = group player;
(hcLeader _group) hcRemoveGroup _group;
player hcSetGroup [_group];