Package: apt Version: 1.8.1 Here it says Invalid archive member.
But it doesn't say what package has the Invalid archive member. It says three packages have the Invalid archive member? # aptitude ... Do you want to continue? [Y/n/?] E: Invalid archive member header 9Ls--------------[BINARY MESS --Dan] E: Prior errors apply to /var/cache/apt/archives/gcc-9-base_9.1.0-2_amd64.deb E: Prior errors apply to /var/cache/apt/archives/curl_7.64.0-3_amd64.deb E: Prior errors apply to /var/cache/apt/archives/libcurl4_7.64.0-3_amd64.deb debconf: apt-extracttemplates failed: dpkg: warning: downgrading libobjc4:amd64 from 9.1.0-2 to 9-20190428-1 (Reading database ... 150517 files and directories currently installed.) Preparing to unpack .../gcc-9-base_9.1.0-2_amd64.deb ... Unpacking libobjc4:amd64 (9-20190428-1) over (9.1.0-2) ... dpkg-deb (subprocess): decompressing archive member: lzma error: compressed data is corrupt dpkg-deb: error: <decompress> subprocess returned error exit status 2 dpkg: error processing archive /var/cache/apt/archives/gcc-9-base_9.1.0-2_amd64.deb (--unpack): cannot copy extracted data for './usr/lib/x86_64-linux-gnu/libobjc.so.4.0.0' to '/usr/lib/x86_64-linux-gnu/libobjc.so.4.0.0.dpkg-new': unexpected end of file or stream Errors were encountered while processing: /var/cache/apt/archives/gcc-9-base_9.1.0-2_amd64.deb E: Sub-process /usr/bin/dpkg returned an error code (1) dpkg: dependency problems prevent configuration of gcc-9: gcc-9 depends on gcc-9-base (= 9.1.0-2); however: Version of gcc-9-base:amd64 on system is 9.1.0-1....