Error: content relocation could not be completed

Did you try my suggestion below of starting in safe mode and trying to move the sound library then? - that worked for me after trying everything else

This worked like a charm- using the App cleaner to uninstall LogicX and then reinstalling it.

COM.APPL.MUSICINSTALLERHELPERTOOL enable full disk access.

YOu're welcome

COM.APPL.MUSICINSTALLERHELPERTOOL enable full disk access.

BENG! Was right! safe mode worked!

I can confirm that in Big Sur you must give full access to com.apple.musicapps.InstallerHelperTool.

Thanks for this. The line item for the box I had to check under Full Disk Access was a bit different though.

It was listed as:

com.apple.musicapps.InstallerHelperTool

I checked that box and it worked as noted. This may be new to Big Sur which is the OS my 2018 macbook is running.

Thank You!

I had to re-install the program and followed the above procedure, and it worked eventually!

Did you try restarting in safe mode (hold shift on System startup) before opening logic and then relocating the sound library like we discuss above?

Do not update Logic Pro X without backing up your latest version.

To back up the application, change the name. In this case, change the name of Logic Pro to the version it is. I'm using Logic Pro 10.5.1.

Transfer the Logic Pro application to another Mac (I'm running 10.15.7). Once the transfer is done, started the entire relocation process over.

Regardless if Logic Pro 10.6.1 or 10.5.1 is opened the Sound Library is being read from the new external location. I've attached screenshots showing the error message and other images.

Ooo that sounds like a really interesting idea. I've just created symlinks for all the different folders inside the application support/logic folder and that seems to be working (although logic still thinks that all my sound library is still on my hdd so i have to download in sections. (also I couldn't just create one for that logic folder as it said i didn't have permissions and wouldn't let me change them to read/write for some reason) I'm tempted to just delete everything and try the safe mode idea you suggest though as that might be cleaner in the long run. Thanks so much everyone!

Then try the symlink option as that should work -

you move your library manually and create symlinks on your HD in the library.

the only downside of this is that your computer will still think everything is on the HD but it does work (or at least Did for me) - the “safe mode” option was the best and cleanest solution I found after weeks of trying other options though and has been fine since (Including spending hours on the phone to Apple support) so might be worth checking that’s definitely not working first.

Logic just showed up normally for me in the applications folder so not sure I’m afraid. Try reinstalling logic maybe? (Doesn’t take long)

The fix did not work for me. I ended up manually creating the symlink to the external drive. Definitely related to the Big Sur update. Swapped my Time Machine HD for some reason too.