OK, I only had problems with a couple of plugins:
1) MovingPictures caused MP Config (when clicking on Plugins) to give an error about Cornerstone and crash and when I copied Cornerstone.dll and Cornerstone.MP.dll across, it then complained about nlog.dll. I found this in the main Mediaportal folder and once I copied this across to 1.2.3 it was OK, but I'm not sure why a plugin needs a .dll in the main folder.
2) Same with SubCentral, that also needs nlog.dll in the main folder.
3) MyLyrics needs LyricsEngine.dll which I also found in the main folder.
Happily, even with all the plugins copied across (except for MyLyrics and LyricsEngine.dll, which I decided I don't need) 1.2.3 seems to be fine and certainly the TV part isn't having any problems
1) MovingPictures caused MP Config (when clicking on Plugins) to give an error about Cornerstone and crash and when I copied Cornerstone.dll and Cornerstone.MP.dll across, it then complained about nlog.dll. I found this in the main Mediaportal folder and once I copied this across to 1.2.3 it was OK, but I'm not sure why a plugin needs a .dll in the main folder.
2) Same with SubCentral, that also needs nlog.dll in the main folder.
3) MyLyrics needs LyricsEngine.dll which I also found in the main folder.
Happily, even with all the plugins copied across (except for MyLyrics and LyricsEngine.dll, which I decided I don't need) 1.2.3 seems to be fine and certainly the TV part isn't having any problems