A few days ago, I started getting the following error when performing
E: Repository 'http://ppa.launchpad.net/webupd8team/java/ubuntu bionic InRelease' changed its 'Label' value from 'Oracle Java (JDK) 8 / 9 Installer PPA' to 'Oracle Java (JDK) 8 Installer PPA' N: This must be accepted explicitly before updates for this repository can be applied. See apt-secure(8) manpage for details.
If I remove the key
/etc/apt/trusted.gpg.d/webupd8team_ubuntu_java.gpg pub rsa1024 2010-05-04 [SC] 7B2C 3B08 89BF 5709 A105 D03A C251 8248 EEA1 4886 uid [ unknown] Launchpad VLC
apt-key del, I (obviously) get
W: An error occurred during the signature verification. The repository is not updated and the previous index files will be used. GPG error: http://ppa.launchpad.net/webupd8team/java/ubuntu bionic InRelease: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY C2518248EEA14886
Thanks for any further help with this.