Here are several ways for you to fix File system verfiy or repair failed. :(-69845). Except for this error code, you mentioned you have received com.apple.DiskManagement.disenter error 0 and File system exit code is 8, don't worry, both of those solutions will be included.
"com.apple.DiskManagement.disenter error 0", which indicates there are some problems on the drive or macOS, making the disk even cannot be mounted by the Mount feature in Disk Utility. You can try to restart your Mac or check if the file system of the drive is compatible with macOS. If the error still exists, continue with other solutions.
You mentioned that you received these two errors "File system verfiy or repair failed. :(-69845)" and "File system exit code is 8" when you run First Aid to fix your disk, which are caused by a corrupted file system on the drive. It can happen on the internal or external hard drive, USB flash drive, or SD card on a Mac running any version of macOS.
You can take the below quick solutions to try to fix these two errors.
- Plugging the drive into another computer to check whether it mounts correctly, then replug it on Mac to run First Aid again
- Use another USB cable
- Unplug the drive and replug it into a different port
If the above three ways are not working, you can take the following methods and rerun First Aid in Disk Utility until the error has been fixed.
- Restart your Mac
- Reformat the drive in Disk Utility
- Replace it or send it to repair