Retroactive was updated on Feb. 18th to version 2.1 to fix some errors. This was also mentioned from the author:
“Retroactive only receives limited support. You should transition from Retroactive to a wide range of supported apps, many of which are built into macOS or free to download.”
I wanted to install iTunes 10.7 CoverFlow running Sonoma on an M1 Air and it did work for the most part except for one issue: when selecting the Settings/Preferences, some changes would be made and others were ignored. Also, iTunes would crash after selecting “OK.” The crashing also happens if I select the Settings under Sonoma running on my old 2012 Mac Mini using OCLP but in that case, the settings are saved and you just reopen iTunes. Since I don’t tend to change anything once it’s all set up, that is not an issue for me but on the M1, the settings would not save properly.
The solution was to create another iTunes library for the M1 on my 2012 Mini and simply copy that over to the M1. After that, it worked fine and I could change the settings although the program will still crash but when you reopen, the changes were saved. Just copying over the preference file is not enough. There is some interaction with the iTunes library that affects the situation. I’m amazed that such an old iTunes version even works on the M1 and the CoverFlow feature works fine which is important to me.
One other issue: I found that even though I disable the Music Store on the 2012 Mini under iTunes running Sonoma, it would reappear every so often as something (maybe the Music app) causes the preference file to update. The solution is to set up iTunes the way you want it and then save a copy of the preference file (under User/Library/Preferences/com.Apple.iTunes.plist) to another location such as Documents. The create an Automator app to replace that preference file with the original one if it changes. I set that up to change it on startup under Login items.
I tried one of the newer iTunes versions which I think was the 12.6 one and it did not have any issues with saving Settings/Preferences under Sonoma but the version 11 one did like version 10.