It started a lot during the advent calendar. I'd click a square(date) and a popup would come up saying Oops, sorry this page is busy... or something like that.. I thought it was just nothing. But it happened 90% of the time when I'd click a box for the first time. Now, I'm noticing it doing it on high roller, turf wars, and other random events. Have had this happen on multiple computers.. (for Mob Wars)
Yes, I've noticed it like that... Maybe I miss-remember but I think it happens With reward, too... I could be mistaken though..
Yeah this is something that we're aware of and are trying to work on minimizing. That screen that you're seeing is there to prevent an error that occurs when people take an action and don't get a reward. It's annoying, but it's definitely the lesser of two evils.