当我使用时出现以下错误apt-get
Reading package lists... Error!
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/graphics-drivers/ppa/ubuntu eoan InRelease: Splitting up /var/lib/apt/lists/ppa.launchpad.net_graphics-drivers_ppa_ubuntu_dists_eoan_InRelease into data and signature failed
W: Failed to fetch http://ppa.launchpad.net/graphics-drivers/ppa/ubuntu/dists/eoan/InRelease Splitting up /var/lib/apt/lists/ppa.launchpad.net_graphics-drivers_ppa_ubuntu_dists_eoan_InRelease into data and signature failed
W: Some index files failed to download. They have been ignored, or old ones used instead.
E: Clearsigned file '/var/lib/apt/lists/ppa.launchpad.net_graphics-drivers_ppa_ubuntu_dists_eoan_InRelease' contains unsigned lines.
E: The package lists or status file could not be parsed or opened.
它会阻止 Synaptic Package Manager 打开，并且还会显示在通知区域。我该如何摆脱它？提前致谢。