I have just upgraded to MC22.
I took the opportunity to copy my Cover Art folder from the default MC21 location to a new, non-version specific location, so that future upgrades will point to the correct folder from the start. So now my Cover Art is in "G:\Cover Art". I made that change, then did a final manual backup of MC21, before doing the upgrade.
Actually I forgot to turn off MC21 starting with Windows before upgrading, but the upgrade process properly turned off MC21 startup and turned on MC22 startup, as per my settings. Cool.
Not so cool. I closed MC21 before upgrading, and MC22 didn't find my old library, so I had to stop the timed automatic import process count down before it started importing all my media again, and then do a Library Restore to get my library back.
Even after a full restore including Library, Playlists, and Settings, the Cover Art folder changed back to the default MC22 location, rather than my new locations at "G:\Cover Art". Also, the back file location was still pointing at the MC21 location, when it really should point to the new MC22 location. Maybe that issue is because I restored from the MC21 location... But still, I don't want MC to start making automatic MC22 backups in to the MC21 location. That has always been an issue with MC major version upgrades though. I don't change that setting to a generic location because backups are version specific, unlike Cover Art, so they should be in version specific directories.
Did guide service/download settings all transfer over and work without tweaking?
The Guide Load process settings all seem to have come across successfully. I will see tomorrow if they run correctly.
Did channel icons transfer over automatically?
As above, I moved my Cover Art to a new location. My Channel icons are stored as Cover Art for the TV Channel files, so they are in the "Cover Art\Files" directory. As no thumbnails are moved over with the upgrade, channel icons weren't immediately available, but they appeared once MC22 built their thumbnails, as did all Cover Art in all views. That only took a few minutes. It isn't worth copying over thumbnails as it is an indexed database. Better to just copy the Cover Art files and let MC rebuild all thumbnails.
Did all recording rules transfer over?
They appear to have come across fine.
Recording Rules are stored in the file "C:\Users\[User ID]\AppData\Roaming\J River\Media Center 21\Library\tvrecording.xml". That file appears to be backup up properly, and therefore is transferred to MC22. I compared the MC21 and MC22 versions, and they are identical.
Does anything look different in Theater View? guide or tv series
I did also have to copy my custom Theme over from MC21 to MC22. That is a directory named to match the Theme name, and is stored in "C:\Program Files (x86)\J River\Media Center 21\Skins\Theater View\Themes". My Theme is called Tiffany, so I just had to copy the "Tiffany" directory to "C:\Program Files (x86)\J River\Media Center 22\Skins\Theater View\Themes". If I had any custom skins no doubt I would have had to copy those across as well.
What I found that was a bit annoying was that my carefully curated and sequenced list of TV Channels was not carried over, even though I did a library restore with the check boxes ticked for Library, Playlists, and Settings. What I found was that the file "TV Shared Settings.ini" in the directory "C:\Users\[User ID]\AppData\Roaming\J River\Media Center 21\Settings" was not included in the backup, and hence was not restored. I shut down MC22, copied the file across to "C:\Users\[User ID]\AppData\Roaming\J River\Media Center 22\Settings", restarted MC22 and my crated list was back. That file only holds the sequence of TV Channels as defined in "Options>Television>Manage Channels", so I would think it should be part of the backups, and be restored with the "Settings" part of the library restore.
Yaobing?
Other than the above, Theatre View looks as it should. I haven't customised the menu system a great deal, because I know the pitfalls of doing so, but the changes I have made, which consist of a few extra views and rules for display, seem to have come across fine.
So, did you see any other problems yourself, or haven't you tried to upgrade yet?