Force installation of debian package to overcome false error message

[The Liquidator]

Hi I'm trying to install Epsons iscan software for an Epson DX4400 MFP.

I need to install 3 packages:

iscan data - this must be first otherwise the following files have dependency errors
iscan
iscan plugin for the specific model.

The first 2 install fine with the Qapt package installer. However, the 3rd won't as I get an error "An older version is available in a software channel". I know there isn't as it's only available via download. In an attempt to clear the error I uncheck everything in Muon. I then try to install and get the error message "A newer version is available in a software channel" - Yes, it now says "newer"! It makes no sense at all to me.

Can someone please advise me how I can force the system to let me install this package?

Many thanks

[arochester]

Have you tried: gdebi ?

My recollection is that it will issue a warning about older/newer versions, but that it will still allow the installation of the package you have chosen.

[Teunis]

I use this software and found the Qapt installer has issues, I installed gdebi (gtk or kde, both work) and was able to install.
Yes it is important to first clear all old instances and then do it in the proper order as explained in the pdf.

[The Liquidator]

Thanks - I had forgotten about gdebi.

Gdebi-kde installed the package without a hitch - no error messages either.