Shame on you!
The game server gets the updated gem and gold inventory from the clients only, which do the calculation themeself. The server just checks whether the balance is reasonable, but it does not track alchemy and all this stuff accurately, hence sometimes the cheat protections is triggered falsely, although this is supposed to be reduced with the 2.14 patch. Notably using the item "AlchemistsStone" used to trigger the cheat protection, but I think this is supposed to be already fixed in 2.14. Are you using the newest patch?
However, the bug-thread records some issues with blood-slaves and blood-sacrifices, so did you mess around with virgins lately? Shame on you again!
So check the gem purses of your commanders and see whether someone does hold more gems or blood slaves than he should and post the circumstances to the bug thread in order to help finding the source of the bug...
BTW, if you are playing alone, you can turn of cheat detection in the game creation menu, provided that you decided to trust yourself in the future now that you have been caught once...