We think we might have found the cause of this one… it actually involves a timeout at the START of the battle.
The timeout might be caused by anything between the device and our servers (inclusive of both), which means server latency, internet dropouts, or generally slow connections… possibly a combination of one or more of them.
It’s the same “sync” error that was previously received at the end of battle on the OLD servers, it’s just that NEW servers are passing back a slightly different message that the game can’t display correctly.
We’ll investigate tomorrow and see if we can push out a hotfix. No promises on a quick fix unfortunately, as it’s @Andrew’s son’s first birthday, so he’s out on leave tomorrow! I’ll see what I can do about it though!