Error code

macOS -34018

MACOS-34018
System Error Code· A POSIX/system errno returned when a system call fails.

What it means

Keychain entitlement missing (errSecMissingEntitlement) — an app tried to access a Keychain item but lacks the required entitlement..

How to fix it

  1. Delete the existing Keychain entry for the app and let it recreate one.
  2. if building the app ensure correct entitlements are set in Xcode.
  3. reset Keychain Access if many items are affected.

Not affiliated with macOS. Answer summarized from the manufacturer's manual linked above; consult that source for the authoritative procedure.