Unrepairable error in disk structure in Onyx I've run Onyx 3.1.7 and received the following disk structure error:

Error: -69845: File system verify or repair failed
Underlying error: 8: POSIX reports: Exec format error

The disk needs to be repaired.


I've rebooted system in recovery mode and attempted to run the First Aid with use of the Disk Utility, however, after rebooting and running Onyx again I've arrived at the same error. The System is running on el-capitan with 500GB flash storage.
Have you tried booting into single user mode (hold down Cmd-S at startup) then at the prompt executing the command fsck -fy until no errors appear? When you're done, type reboot at the prompt.