我无法执行，apt update因为它引发了以下错误。
Reading package lists... Error!
W: Target Packages (partner/binary-amd64/Packages) is configured multiple times in /etc/apt/sources.list:45 and /etc/apt/sources.list.d/xenial-partner.list:4
W: Target Packages (partner/binary-i386/Packages) is configured multiple times in /etc/apt/sources.list:45 and /etc/apt/sources.list.d/xenial-partner.list:4
W: Target Packages (partner/binary-all/Packages) is configured multiple times in /etc/apt/sources.list:45 and /etc/apt/sources.list.d/xenial-partner.list:4
W: Target Translations (partner/i18n/Translation-en_IN) is configured multiple times in /etc/apt/sources.list:45 and /etc/apt/sources.list.d/xenial-partner.list:4
W: Target Translations (partner/i18n/Translation-en) is configured multiple times in /etc/apt/sources.list:45 and /etc/apt/sources.list.d/xenial-partner.list:4
W: Target DEP-11 (partner/dep11/Components-amd64.yml) is configured multiple times in /etc/apt/sources.list:45 and /etc/apt/sources.list.d/xenial-partner.list:4
W: Target DEP-11-icons (partner/dep11/icons-64x64.tar) is configured multiple times in /etc/apt/sources.list:45 and /etc/apt/sources.list.d/xenial-partner.list:4
W: Target Packages (partner/binary-amd64/Packages) is configured multiple times in /etc/apt/sources.list:45 and /etc/apt/sources.list.d/xenial-partner.list:4
W: Target Packages (partner/binary-i386/Packages) is configured multiple times in /etc/apt/sources.list:45 and /etc/apt/sources.list.d/xenial-partner.list:4
W: Target Packages (partner/binary-all/Packages) is configured multiple times in /etc/apt/sources.list:45 and /etc/apt/sources.list.d/xenial-partner.list:4
W: Target Translations (partner/i18n/Translation-en_IN) is configured multiple times in /etc/apt/sources.list:45 and /etc/apt/sources.list.d/xenial-partner.list:4
W: Target Translations (partner/i18n/Translation-en) is configured multiple times in /etc/apt/sources.list:45 and /etc/apt/sources.list.d/xenial-partner.list:4
W: Target DEP-11 (partner/dep11/Components-amd64.yml) is configured multiple times in /etc/apt/sources.list:45 and /etc/apt/sources.list.d/xenial-partner.list:4
W: Target DEP-11-icons (partner/dep11/icons-64x64.tar) is configured multiple times in /etc/apt/sources.list:45 and /etc/apt/sources.list.d/xenial-partner.list:4
E: Unable to parse package file /var/lib/apt/lists/linux.dropbox.com_ubuntu_dists_xenial_main_binary-i386_Packages (1)
E: Unable to parse package file /var/lib/apt/lists/linux.dropbox.com_ubuntu_dists_xenial_main_binary-amd64_Packages (1)
W: You may want to run apt-get update to correct these problems
E: The package cache file is corrupted