Appodeal doesn't works

Hi, I have a new account with Appodeal. The 1st day all works fine, a good ecpm and good revenues. But yesterday and today, the banners don’t work. I get this message on logcat:

“Failed to load ad: 0”

The implementation are correct, but I don’t understand what happens with this. Someone has the same problem?

Sounds bad if there is no implementation issue from yourside.

I tried the banner today in my new app and it is working well.

everything is working good for me, check your code