Error 69877
Apple macOS
Severity: CriticalWhat it means
Error 69877 in Disk Utility means the APFS (Apple File System) operation failed.
This commonly appears when trying to resize, partition, or erase an APFS volume.
Try running First Aid first, or boot into Recovery Mode to perform disk operations.
Affected Models
- macOS Sonoma
- macOS Ventura
- macOS Monterey
- macOS Big Sur
- macOS Catalina
Common Causes
- Cannot resize APFS container while the disk is in use (boot disk)
- APFS filesystem corruption
- Disk Utility operation conflicting with FileVault encryption
- Insufficient free space for the requested partition change
- T2 or Apple Silicon security preventing disk modification
How to Fix It
-
Run First Aid on the disk: Disk Utility > select the disk > First Aid.
First Aid checks and repairs filesystem errors.
Run it on both the volume and the container. -
Boot into Recovery Mode and run Disk Utility from there.
Intel Mac: restart and hold Cmd+R.
Apple Silicon: hold the power button until you see Loading startup options.
Disk operations often work in Recovery when they fail from the running OS. -
If resizing a partition: make sure there is enough free space.
APFS needs free space to reorganize data during a resize.
Free up space on the drive before attempting to resize. -
If erasing: disable FileVault first.
System Settings > Privacy & Security > FileVault > Turn Off.
FileVault encryption can interfere with disk erase operations.
Frequently Asked Questions
What is APFS?
APFS (Apple File System) replaced HFS+ as the default Mac filesystem in 2017.
It is optimized for SSDs and supports features like snapshots, encryption, and space sharing.
Will fixing this error erase my data?
First Aid does not erase data — it only repairs filesystem structures.
However, if you need to erase and reinstall, all data will be lost.
Always back up with Time Machine before disk operations.