Comment 74 for bug 1811504

> Mick (miin) wrote on 2020-03-27: Re: scan with Laserjet MFP-M28 fails #62
> Scanner works with hplip-3.20.3 and updates enabled.

Yes, this is right. Both it works with hplip-3.21.2.

This page is one of the google targets when searching why 3.18.4 not working (doesn't allow to scan with Laserjet MFP-M28 failing after "Warming up..." when "Scanning...").

Maybe please keep for other people (if they use similar environment like I do, but I think that for Ubuntu this info could be useful too in someway). For rhel I used these commands to reinstall 3.21.2 above default 3.18.4:

1. Download from HP 3.21.2:
https://developers.hp.com/hp-linux-imaging-and-printing/gethplip

2. Reinstall default version:
sudo dnf reinstall hplip hplip-common hplip-gui hplip-libs libsane-hpaio

3. Install 3.21.2 above default version with dependency check skipping (since non possible to remove default one):
sudo rpm --nodeps --force --install ~/install/hplip-3.21.2-RHEL8-x86_64.rpm

4. Fix python to be both /usr/bin/python and 3.6 one (that is default one for my system):
sudo ln /usr/bin/python3.6 /usr/bin/python

5. Download required hp-plugins for 3.21.2:
sudo hp-plugin

6. Now scanning works Ok:
hp-scan -g -r200