Yeah.. a bit disappointing, especially if you're doing those negative balance negotiations, eventually spending some diamonds... (free ones, not a financial loss, but still annoying since they could have been used in a better way.)
Can you at least explain what's going on behind the scenes?
GE is a feature that works quite well on live servers, so you're obviously fiddling with it here on beta.
(If you're working on a totally cooooool new feature, maybe reactions about losing time, units, goods, diamonds & guild power [bonus] will get a bit less disappointed...)