Only it wasn’t. GoW hung up on me, continuously playing some tsching sound. On the bright side: I didn’t loose the fight (so didn’t loose my bonus star in the next battle). On the other hand I lost my ‘investment’, some 500 gold or so to invade. 
Fun fact: I solved the confusion I had why the ‘chess board’ looks different from battle to battle. It shows clearly that it’s partly transparant and the background shows the invaded (or defended) kingdom. Never realised that before!
So you invested 500 Gold into knowledge!
Ya-huh! I love all the full screen Kingdom artwork 
I’ll pass this to @Full, but I have a feeling this has been resolved in the next update. Will pop back if this isn’t the case!
Edit: Confirmed, fixed next update
Strange, I wouldn’t have thought that was a bug but by design? I think it looks lovely, once you know what you’re looking at.
Ah I meant the lock up, not the background 
Oh, I thought the lockup was just a glitch, not a bug. This was Windows 10 after all.
