NO_PUBKEY error when checking for updates

[SuperCheezGi]

I fired up Update Manager and I checked for updates and I get this error:



and I tried

sudo apt-key adv --keyserver keyserver.ubuntu.com --recv-keys 531EE72F4C9D234C

but this gave me THESE errors:



and I have no idea how to fix this. I assume the second error is because of my internet connection, but that's an assumption. I think I should try again later and by running the code above I should get this error sorted out right?

[zvacet]

I know this is not thing you are looking for,but maybe to remove that ppa from source list and try to add it again with key.Just suggestion.