If you need more storage for a Final Cut Pro library
If you run out of space on the volume where the Final Cut Pro library you're currently working with is stored, you may see an alert. When this happens, you can get additional storage and move the library to the new storage device. You can also try to create space on the current volume by deleting items like unwanted clips or by deleting unused render files.
Before proceeding, make sure you back up your Final Cut Pro libraries, media and the Final Cut Pro application.
If one of these alerts appears while working on a Final Cut Pro project, the volume where the current library is stored may be running out of space or is stored on an external storage device that isn't formatted as APFS:
The operation couldn't be completed. Permission denied. [Library name] is already in use by [user account name] on [Mac sharing name].local.
The document [Library name] is already in use by [user account name] on [Mac sharing name].local.
The document [Library name] could not be opened. Permission denied. [Library name] is already in use by [user account name] on [Mac sharing name].local.
The Library [Library name] is damaged. The item [item name] could not be read.
If you see one of these alerts, restart your Mac before proceeding with the steps below.
Determine which volume the library is stored on
If you can open Final Cut Pro, select the library in the Libraries sidebar of Final Cut Pro. The name of the volume, such as Macintosh HD, appears in the Library Properties inspector on the right.
If you can't open Final Cut Pro:
In the Finder, press Command-F to access advanced search criteria.
Chose View > as List (or press Command-2).
Click the search criteria pop-up menu that says Any, then choose Other.
Enter "Final Cut Pro library" in the field next to the pop-up menu.
Choose View > Sort By (or Group By, depending on your settings), then choose Date Modified. The most recently modified library will be near the top of the list. Ignore the libraries with timestamps for names, such as "20240401_0915_CDT".
Control-click the library in the list, then choose "Show in Enclosing Folder". The library location path will appear at the bottom of the Finder. If the path doesn't appear, press Command-Option-P to see the path.
Check available storage space
Check the available storage space on the volume where the current library is stored.
In the Finder, choose Go > Computer.
Select the volume where the library is stored.
Choose File > Get Info, or press cmd-I.
In the General section of the Info window, you can see the available storage space on the volume.
If the volume where the library is stored is at or close to capacity, move the library to a location with available space, like an external storage device, and make sure it's formatted with the APFS format.
Check library size
If you need to move the library to a location with more space, check the size of the library to get an idea of how much additional storage space you'll need
In the Finder on your Mac, locate the affected library.
Select the library in the Finder.
Choose File > Get Info, or press cmd-I.
In the General section of the Info window, you can see the size of the library file.
Check the format of your storage device
If the library is on an external storage device that has plenty of available storage space but you are still getting alerts, make sure it's formatted as APFS. If the device is formatted with an unsupported format, such as ExFAT or NTFS, reformat your storage device:
Copy the affected library and any other libraries stored on the device to a temporary location.
Copy the libraries back to the properly formatted storage device.
Move the library to a new storage device
If you need additional storage, move the Final Cut Pro library to a new storage device formatted as APFS. Additional storage dedicated to your Final Cut Pro libraries also ensures that you'll have adequate space for future projects.
External storage devices are sometimes sold pre-formatted with a Windows file system format such as ExFAT or NTFS. Make sure you reformat the device as APFS for best performance with Final Cut Pro libraries.
Make sure you regularly back up your app and libraries.
If the library is stored on the startup disk
If your Mac startup disk (usually called Macintosh HD) is at or near capacity, you can move the Final Cut Pro library to a new storage device formatted as APFS.
If you don't know the name of your startup disk:
Choose Apple menu > System Settings.
Click General in the sidebar, then click Startup Disk on the right. Your startup disk appears selected.
Before you move a Final Cut Pro library that's currently stored on your Mac startup disk, you should back up your Mac.
Delete items from your library
You can delete unwanted clips, projects or an entire event from your library to create space on the volume. When you delete a clip or a project from an event or delete an entire event, the source media files are moved to the Bin. Remember to empty the bin after you've deleted items.
Manage render files
Final Cut Pro creates temporary video and audio render files for segments of your project that Final Cut Pro can't play in real time. By default, rendering occurs in the background, but you can also manually control rendering for a project or a portion of a project. Render files can accumulate over time and take up space.
Actively manage render files to help keep space available for your Final Cut Pro libraries. You can delete unused render files in selected events. You can also delete render files for clips, projects, events or libraries. You can always regenerate render files from original media.