I have a question. Is there something I am not aware of that would cause all of my territory to go to a Coalition leader if I am a part of that coalition and I attack another coalition member? I think I may have been setup.
A) As a member of a coalition, you cannot attack other members of that coalition at all. Only after you are thrown out or drop out of the coalition you can. It's not possible otherwise.
B) If you're saying that what you've been told is that the game will just give your entire country away to someone else, coalition leader or not, then no. That's proposterous. You have indeed been set up if that's what you were led to believe.
C) Revolts can occur in provinces with a morale below 35%. If they are not suppressed by a sufficiently strong garrison (at 35% morale that would be 6 dudes), those provinces can revolt (at a random chance determined from probability of an uprising, which itself is determined from morale and then adds a dice roll) and change allegiance. They will have a higher chance of joining countries with high global popularity, plus, anecdotally, a country they may have previously belonged to, should that country still exist.
Those are the conditions for revolts. A province at low morale and not enough firepower in it to suppress the uprising. Nothing else will cause a revolt far and wide.
There is NO possible way that your entire country can transfer to ANY player in a game round. The ONLY possibility is if your country consists of ONE province and it is down around 3 percent morale it could revolt to somebody.
I had approximately 8 or 9 provinces, and at the behest of the coalition leader, attacked a fellow coalition member who had dropped from the game, as soon as that happened, I lost nearly 80 troops, 2 artillery pieces, and ALL of my provinces. The moral was not that low and I am thinking the coalition leader may have been exploiting a glitch or something. I definitely feel like I got setup so he could take my land without firing a shot.
It could be that they stationed troops at all your provinces, and that you left your provinces (almost) empty. So all it takes is for them to declare war, and all your provinces will be captured by them immediately. When a player has no provinces left, all his units will immediately disappear.
ScaredyCat's explanation is currently the most reasonable one to me as well although the hole in it is how you would miss that they've set up troops in every single one of your provinces before this went down. If and when that was happening, that really should have raised a number of red flags.
Either way, yeah, you got played like a fiddle I'm afraid.
Having low morale on a province can lead to a revolt (below 30%). When the province revolts it declares itself as part of another country.
Daily consumption is quite important as failing to fill it leads to a drop of morale. Running out of resources (especially food) can start a decline in morale, as will declaring war with multiple countries.
To raise morale in a province you can either use Goldmarks or fill their daily consumption and the morale will raise slowly at daychange or station troops with high morale to suppress rebellions. Also, building fortifications and placing your capitol close to provinces can help.
Conquered provinces are set to 25% morale at the time of capture, this increases the chance of rebellion for these provinces at the day change. At each day change the morale will rise slowly in good conditions, or with poor conditions the morale could remain stable or fall. Factors that reduce morale include the number of wars, distance from capital, and the morale of neighboring provinces.
REMEMBER: Garrison troops left inside the province center will reduce the revolt risk in your new province. A strong enough force will completely suppress a rebellion, while a weak force of just one or two units generally have a chance to be overcome by the rebellion, or to join the rebellion.
That has happened to me, I kept getting my allies land until he got attacked and lost all of it. He did un-ally me, because of his suspicion of my new-gains, I didn't know what was going on, but until I got murdered like my 'ally', I noticed it was his provinces revolting.