Hallo!
I have installed the version 2.2.3 final and I would upgrade to 2.0.17.1 , can I have information for upgrade?

Sorry it took someone so long to answer! Ok... How long has the 2.2.3 Site been up? How much data are we talking about here? How many hours have you put into the site? Can you pm a link if you dont want to post it here?

I personally have never use the 2.2.x versions and have never attempted the downgrade myself. I have only installed and tested those versions.

This downgrade script has been tested only on 2.2.3RC1 according to Mith!

Please do not attempt this downgrade yet. Let a few more people chime in first. You will need to make a few backups of your site first. In fact make backups of the backups just in case.

There are many threads about this here in the forums. I'll try to post some for you. Maybe some other people might post as well with some good threads of success and some failures as well that have gone bad.