old shares causing problems

Dear All,

When I open GarageBand I get a popup asking me to provide credentials for a server. Unfortunately that server no longer exists, and hasn't existed for several years. When I cancel out of the login popup, I get an error window saying the server is unavailable (duh), which cannot be dismissed. Any dismissal of it causes it to reappear, and it is on top of all other windows. I have to move it to the side for the duration of my session.

GarageBand is using my iTunes library as a resource and I suspect the old server is somehow referenced in there, but when I text search the iTunes library xml file (a copy of the library in xml form) there is no reference to it at all. I am reasonably well-versed in systems operation and administration and have done a lot of searching but cannot find where this is coming from.

I am at a complete loss on how to find this old reference to an ancient server that has been gone forever and get GarageBand to stop looking for it. This is super frustrating.

Any help you might offer would be appreciated.

Sincerely,

H.