We are aware of low ad inventory issues, but can you contact our support team so we can verify that nothing else is causing a problem? https://animationthrowdown.zendesk.com/hc/en-us/requests/new
It would be good to be able to switch between menu screens without having to exit out of one first. (i.e. go straight to upgrades while in achievements, that sorta thing)
Can you send us the console log error (press F12) and the console tab