Logic Pro X "Sampler Instrument (mellotron) not found."

I've seen a few people have this question, and I've just run into the issue as well. I just recently backed up my entire computer on an external drive, including the Audio Music Apps section from the Library.

Now my projects that use the vintage mellotron plugin show up with an error message when every time I open the project, specifying the setting of mellotron I was using in the session, example Sampler Instrument "strings and flute" not found OR "flutes" etc. And that same mellotron track in the project defaults to a sound I've never heard before, like distorted vibes meets electric piano -- not the mellotron sound I previously selected. I am able to reload the mellotron sound by opening up the plugin and reselecting the sound I want, but I cannot do that and keep my specific settings in that instrument. :(

Anyone have any solutions to this problem yet? Thank you.