In trying the quest "Opportunity", I clicked on the quest icon, pick my unit (inf w/ hero) and the battle icon. I get the blue globe burning icon and about 10-15 sec later get a disconnection/refresh error. I have tried this on 2 different systems (both Chrome Version 26.0.1410.65). Someone mentioned they had an issue with barracks being lower than 3. Once I upgrade Barracks to lvl 3 I was able to battle.