Invalid instrument library

Is that the error message you see? "The Instrument File is invalid. GarageBand expects a valid Instrument Library folder in /Library/Application Support/GarageBand. Please choose a valid Instrument Library folder or quit and re-install GarageBand."

Probably the instruments Library is missing from your User Library or System Library or it is corrupted:

Check, if you still have an instruments library, either in the System Library:

/Library/Application Support/GarageBand

or in the User Library:

~/Library/Application Support/GarageBand

If you can't find those libraries, you need to reinstall them, either from your Time Machine backup from a previous system or by reinstalling GarageBand.

In OS Lion the libraries are hidden by default. To reveal them in the Finder, open the Terminal (from Applications -> Utilities) and type into the Terminal window:

chflags nohidden ~/Library; open ~/Library

sudo chflags nohidden /Library; open /Library

You may need to enter your administrator password to do that.

The above will permanently reveal the libraries. If you want to hide them again when you are done, enter the same commands, but set the flag to "hidden".

chflags hidden ~/Library

chflags hidden /Library

Your User Library you can reveal in Lion without changing the "hidden" flag frm the Finder -> Go menu:

When in Finder, select from the Finder menu "Go" -> "Go to Folder", then hold down the option-key until the Library appears in the drop-down menu, select it and enter "return".

Perhaps this article by Pondini will be useful for you to get started with Lion:

Pondini’s OS X Tips: Some Changes in Lion: http://Pondini.org/OSX/LionChanges.html

Regards

Léonie

Hello Kathy,

here is a look at my Instruments Library; I dragged my User Library and the System Library to the Finder Sidebar for easy access, after opening it: You should see at least those eight groups of files.

To help you further I need to know a little bit more about your system: You said your MBP is new and you want to install GB.

• Do you use the reinstalled LIon or did you migrate an older system with a previous GB installation?
• Are you trying to install GB from the App Store or are you using a boxed Version?

I f you already tried to reinstall GarageBand and it did not help, I would deinstall it completely - erase all traces of GarageBand from the System Library (all of Application Support/GarageBand in the System Library), not just delete the Application from the Application Folder and also delete the installed packages:

Locate the GarageBand application, usually stored at /Applications/.

• Drag GarageBand to the trash.
• Launch Terminal, located at /Applications/Utilities/.
• At the command prompt, enter the following:

Sudo pkgutil -forget com.apple.pkg.GarageBand

Press return.

• You will be asked for an administrator password. Enter the password, and press return.
• When the Terminal command prompt displays, type the following:

Exit

Press return.

Close Terminal.

Regards

Léonie

You are welcome, Kathy.

Enjoy your music!

Léonie

I am having the same issue, but I have been unsuccessful in reinstalling the application. I have completely deleted GB (the icon), then searched for any folders and erased them as well. Just to be safe, I followed your instructions, the Sudo pkgutil -forget com.apple.pkg.GarageBand from Terminal and it is still happening.

For clarification, the error message says:

The Instrument Library is invalid. GarageBand expects a valid Instrument Library folder in /Library/Application Support/GarageBand.

Please choose a valid Instrument Library folder or quit and re-install GarageBand.

The files that exist when I "choose file" are: Chordtrainer, Instrument library, Learn to Play, Magic GarageBand, and Templates.

None of files in these folders seem to be selectable.

So, I exited the program and opened Terminal after completely deleting all things GB.
Then, I put in Sudo pkgutil -forget com.apple.pkg.GarageBand as suggested above (both case and space sensitive) and hit Enter

Then, my password and Enter

The screen says: pkgutil: invalid option -- o

Then I typed Exit and hit Enter and closed Terminal. But the problem still persists when I re-download it from the App Store and try to re-install.

Any other help would be fantastic. I have also completed the Repair Disk Permissions as suggested in another support page.

Figured it out, false alarm. go on your main disk library/application/support/garageband and select instument library and choose.