Thanks for your prompt response!
Following is the output for the command : do-release-upgrade -p on Ubuntu 20.04
Checking for a new Ubuntu release
There is no development version of an LTS available.
To upgrade to the latest non-LTS development release
set Prompt=normal in /etc/update-manager/re
Public bug reported:
Ubunut 20.04 internal error encounted while updating
ProblemType: Package
DistroRelease: Ubuntu 20.04
Package: libfreeimage3:amd64 3.18.0+ds2-1ubuntu3
ProcVersionSignature: Ubuntu 5.4.0-70.78-generic 5.4.94
Uname: Linux 5.4.0-70-generic x86_64
NonfreeKernelModules: nvidia_mod
Public bug reported:
An unresolvable problem occurred while calculating the upgrade.
This was likely caused by:
* Unofficial software packages not provided by Ubuntu
Please use the tool 'ppa-purge' from the ppa-purge
package to remove software from a Launchpad PPA and
try the upgrade again.