Snapshot is a set of history files captured at a particular time, capable of being reloaded to restore the earlier state. APFS snapshot is like several panoramas of APFS drive at different times. Thus, whenever our APFS file system goes wrong, we can go back to the previous status of disk.
If APFS snapshot is invalid or the APFS snapshot metadata tree is invalid on macOS, the status of partial data stored on the APFS drive can be affected. It means the snapshot of some files have already been damaged or missingAnd the APFS drive might not be mounted for file accessing as usual. Under this circumstance, we are not allowed to access the APFS drive and files saved on the drive are lost.
Here is a case from forums:
Since I converted my internal hard drive to APFS file system, it worked perfectly. But when I tried to store some files in the drive today, I failed to mount it. Then I checked the drive in Disk Utility, I got an error message saying: "APFS snapshot is invalid". I have no idea what happened. Anyone can help me to fix/repair invalid APFS snapshot error?
Fix APFS snapshot is invalid/Snapshot metadata tree is invalid error on High Sierra
Since Invalid APFS snapshot error on High Sierra is so complicated, the only way is to reformat the APFS drive. But we will face useful data loss if we directly reformat the APFS drive. Therefore, for the security of our important files, we'd better recover lost data from APFS volume which has invalid APFS snapshot error.
Step 1: Recover lost data from APFS volume which has invalid APFS snapshot error with APFS data recovery software
iBoysoft Data Recovery for Mac is the best APFS drive data recovery software that can recover lost data after invalid APFS snapshot error, recover lost data from encrypted APFS volume, recover lost data from formatted APFS drive, recover lost data from unmountable APFS drive, recover lost data from unreadable APFS drive, recover lost data from corrupted APFS drive, recover lost data from inaccessible APFS drive, recover deleted/lost APFS partition, etc.
Aside from APFS data recovery, iBoysoft Data Recovery for Mac can also recover lost data from FAT32 drives, exFAT drives, HFS+ drives, recover lost data from formatted, unmountable, inaccessible, corrupted hard drive, external hard drive, USB flash drive, SD card, pen drive, etc. on macOS Big Sur 11/10.15/10.14/10.13/10.12 and Mac OS X 10.11/10.10/10.9/10.8/10.7.
Tutorial to recover lost data from APFS drive which has invalid APFS snapshot error
1. Launch iBoysoft Data Recovery for Mac.
2. Select the APFS drive which has "APFS snapshot is invalid" error and click "Next" button.
3. Enter password to start searching for lost files on the drive.
4. Preview the searching results, choose files we need, and click "Recover" to get them back.
Step 2: Fix APFS snapshot or snapshot metadata is invalid error by reformatting
1. Launch Disk Utility.
2. Select the APFS drive which has "APFS snapshot is invalid" error on the left part of the window.
3. Click Erase on the top of the window.
4. Complete related information (name, format, scheme), then click Erase.