After I create my team I get a server error. The error code is CLIFFY-XXXXX. I CAN’T screenshot it because it restarts the game too quickly.
It’s a bug when making your team, there should be some restriction on the colors you can use, so when you assemble any team breaking this rule the game borks itself.
You can only use troops that are 
YELLOW or 
GREEN
Ah. OK. I was going to edit and say it didn’t work in the delve either but they should dive it. Thank you.
I apologize for the issues with the Warren Faction last Friday. The team resolved the issue within an hour or two of it occurring. During this time, if you attempted to enter the Delve with Troops that were not Yellow/Green Mana then the game would produce an error. We’ve checked this in our server logs and it does not generate a “starting” log for the battle, so, fortunately, no Sigils would have been lost. Happy new year!