Can someone help me fix this, I tried but I forget how to do this now. I see Opera in the "Software Sources" but I do not have it installed. I may have at one point but uninstalled it.
W: An error occurred during the signature verification. The repository is not updated and the previous index files will be used. GPG error: http://deb.opera.com stable InRelease: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY D615560BA5C7FF72 W: Failed to fetch http://deb.opera.com/opera-stable/dists/stable/InRelease W: Some index files failed to download. They have been ignored, or old ones used instead.
It also has a Check Mark on it, I would think just removing it would solve my problem, though may not be the right way to go about it.