I finally found a solution. I tried various version of HPLIP, and there were apparently completely different dependencies reported as missing, and that would not install.
The problem was Python defaulting to version 2.
The solution was to use Synaptic Package Manager, and uninstall "python-is-python2" and install "python-is-python-3" Immediately HPLIP installs correctly in both Ubuntu 18-04 and 20_04.
I installed Hplip and the plugin:
su hplip-3.20.6.run
su hplip-3.20.6-plugin.run
The problem appears to be that some part of the HPLIP install is not specifying which version of python, so it was defaulting to a depricated version.
Now my MFP m281fdn printer and scanner are working perfectly!
I finally found a solution. I tried various version of HPLIP, and there were apparently completely different dependencies reported as missing, and that would not install.
The problem was Python defaulting to version 2.
The solution was to use Synaptic Package Manager, and uninstall "python-is-python2" and install "python- is-python- 3" Immediately HPLIP installs correctly in both Ubuntu 18-04 and 20_04.
I installed Hplip and the plugin:
su hplip-3.20.6.run 20.6-plugin. run
su hplip-3.
The problem appears to be that some part of the HPLIP install is not specifying which version of python, so it was defaulting to a depricated version.
Now my MFP m281fdn printer and scanner are working perfectly!