I was running the Hyper-V image 7.1.2 but when it offered to upgrade to 7.2.3 it was failing when it was getting the package list.
Give an error along the lines of
[ INFO ] DietPi-Update | APT update, please wait... Hit:1 https://deb.debian.org/debian buster InRelease Get:2 https://deb.debian.org/debian buster-updates InRelease [51.9 kB] Get:3 https://deb.debian.org/debian-security buster/updates InRelease [65.4 kB] Get:4 https://deb.debian.org/debian buster-backports InRelease [46.7 kB] Get:5 https://deb.debian.org/debian-security buster/updates/main amd64 Packages [291 kB] Ign:6 https://download.webmin.com/download/repository sarge InRelease Hit:7 https://download.webmin.com/download/repository sarge Release Fetched 455 kB in 1s (422 kB/s) Reading package lists... E: lzma_read: Read error (10) E: The package lists or status file could not be parsed or opened. [FAILED] DietPi-Update | APT update
Did a quick search for LMZA READ error and the following worked for me.
In the updater, drop to a subshell then delete the contents of this folder
now Exit back to the Updater and hit RETRY and it then installed successfully