Trying to get Xsane and a CanonScan LiDE 400 to play nice

Solution 1:

device `escl:http://127.0.0.1:60062' is a ESCL LiDE 400 HTTP flatbed scanner

The scanner is detected by the SANE escl backend. This is good. What is not good is that it does not work. This is probably a bug in your version of the backend (provided ippusbxd is not on the system and misbehaving).

Fortunately, there is the independent sane-airscan backend to fall back on. On Ubuntu 21.04 it is available and installed by default. What you do on 20.4 is go here. Note the support for your scanner.

Now you move on to this page and download and install ipp-usb and sane-airscan. ipp-usb is much, much better then ippusbxd. Even the author ofippusbxd says his software is not fit for the job.