Can I rollback Library manager to a previous version?

I want to install some Halion patches, but I can’t since my current version of Library manager doesn’t work on El Capitan.

I have updated to Cubase 10.5 Pro, which works normally (I hear 10.6 doesn’t work anymore on my OSx). I haven’t used Librarymanager before, so I don’t know if it worked before the update to 10.5.

Can I just somehow install previous version of just the Library manager to use it with Cubase 10.5? Is it possible? And if yes, how? And if it will work with this version of Cubase, or would I need to rollback Cubase too?

Thank you