cant install or remove anything on 18.04 cause of DPKG error
Your dpkg has wrong version somehow, Ubuntu 18.04 currently has version 1.19.0.5. You need to reinstall dpkg:
Try this:
sudo -i
mkdir /tmp/dpkg
cd /tmp/dpkg
wget http://launchpadlibrarian.net/366329727/dpkg_1.19.0.5ubuntu2_amd64.deb
ar x dpkg*.deb data.tar.xz
tar xvf data.tar.xz ./usr/bin/dpkg
cp ./usr/bin/dpkg /usr/bin/
apt-get update
apt-get install --reinstall dpkg
From can't install software--can I fix missing dpkg?