After upgrading today to macOS 11.2.3, I noticed that my scripts and apps that employ the iTunesLibrary framework are having trouble accessing media information. This includes my app "Dupin" and the script "Media Folder Files Not Added" and a small number of others. Affected apps/scripts will likely be unable to complete an initialization routine and stall at "Indexing" or similar stage. I am actively investigating this issue.
UPDATE, March 9, 2021: After several machine reboots (and fsck, disengaging connected devices and so on; the usual start-up regimens), things are now working as expected. I could not say what caused the issue I was experiencing or why it came and went.