errSecItemNotFound -25300 Full Explanation & Complete Fix Guide

Error Overview

errSecItemNotFound -25300 is a macOS error code/condition. It is produced by the macOS kernel (XNU), a framework (Foundation/CoreAudio), or a system tool (diskutil, xcodebuild, keychain). It signals a specific failure — I/O, file system, code signature, keychain, or build pipeline — surfaced via the GUI dialog, Console.app, or the terminal.

Root Cause Breakdown

errSecItemNotFound -25300 has four typical root-cause layers:

1. Hardware. Failing SSD (I/O errors), bad RAM (memFullErr), or an overheating SoC.
2. Driver/system. SIP/TCC denial, APFS sealed-system volume, or a stale developer path.
3. System. Keychain locked, code signature invalid, or disk utility mount failure.
4. Software. A broken app update, arch mismatch (Apple Silicon vs Intel), or a dyld load failure.

Diagnose top-down: hardware first (cheapest to rule out via swap/memtest), then driver/firmware, then system state, then software.

Multi-Platform Repair Steps

Windows

1. Boot into Safe Mode or Windows Recovery Environment if the OS will not start.
2. Run the diagnostic for this code (see commands below).
3. Apply the fix, reboot, and verify.

# Windows repair toolkit
DISM /Online /Cleanup-Image /RestoreHealth
sfc /scannow
chkdsk C: /f
# Driver verifier to catch faulty drivers (advanced)
verifier /standard /driver *```

#### macOS

1. Boot into Recovery (Apple Silicon: hold power; Intel: Cmd+R).
2. Run Disk Utility First Aid, then reinstall the system/security update.
3. Reset SMC/NVRAM (Intel) or shut down fully (Apple Silicon).

```bash
# macOS diagnostics
diskutil verifyDisk disk0
sudo softwareupdate --list
sudo softwareupdate --install --all
# Reset launch services if an app is rejected
/System/Library/Frameworks/CoreServices.framework/Versions/A/Frameworks/LaunchServices.framework/Versions/A/Support/lsregister -kill -r```

#### Linux

1. Boot a live USB if the installed system will not start.
2. Read the kernel log and run the filesystem check.
3. Repair packages and reboot.

```bash
# Linux diagnostics
dmesg --level=err,warn | tail -50
sudo journalctl -p err -b
sudo fsck -y /dev/sdXN
# apt repair
sudo apt --fix-broken install
sudo dpkg --configure -a```

### Tiered Device Solutions

- **Low-End Laptop (8 GB, integrated GPU):** this code often surfaces as an OOM or driver/thermal issue. Close background apps, cap heap, update drivers, keep the laptop cool. Validate RAM with the [Dev RAM Calculator](/tools/dev-ram-calc/).
- **Mid PC (16 GB, 6–8 cores, discrete GPU):** update chipset/GPU drivers, run SFC/DISM (Windows) or fsck (Linux/macOS), and remove recently added software. Most codes clear after a driver + system-file repair pass.
- **Workstation (64 GB, ECC, big GPU):** check ECC logs, run extended memtest, inspect event/journal logs, and isolate faulty hardware by swapping. Workstations make hardware faults easy to isolate — use that.

### Similar Error Codes Reference

- [Error -36](/error-code/macos/error-36/) — Error -36 guide
- [Error -43](/error-code/macos/error-43/) — Error -43 guide
- [Error -50](/error-code/macos/error-50/) — Error -50 guide
- [Error -108](/error-code/macos/error-108/) — Error -108 guide
- [Error -127](/error-code/macos/error-127/) — Error -127 guide
- [Error -1401](/error-code/macos/error-1401/) — Error -1401 guide

### Common Mistakes To Avoid

1. Disabling SIP globally instead of fixing the specific TCC permission.
2. Force-quitting diskutil during First Aid and corrupting the volume.
3. Bypassing Gatekeeper with xattr -dr on every app as a habit.
4. Deleting system files on the sealed APFS System volume.

### Calculator Recommended Adjustment Params

This code is not directly hardware-bound, but you can still validate your rig with the [Dev RAM Calculator](/tools/dev-ram-calc/) and [Build Time Calculator](/tools/build-time-calc/) before and after the fix.

### FAQ

**Q: What does macOS errSecItemNotFound -25300 mean?**

A: It is a kernel/framework/tool error. See the Error Overview for the exact subsystem.

**Q: How do I fix errSecItemNotFound -25300?**

A: Boot Recovery, run First Aid, reinstall the security update, and clear the implicated cache. See the steps above.

**Q: Is errSecItemNotFound -25300 a virus?**

A: Almost never — most macOS codes are driver/system/keychain/build issues.

**Q: Where are errSecItemNotFound -25300 logs?**

A: Console.app, ~/Library/Logs, or the terminal stderr. Browse more at the [macOS error hub](/error-code/macos/).


### Summary

`errSecItemNotFound -25300` is fixable with a disciplined top-down pass: rule out hardware first, then driver/firmware, then system state, then software. Use the tiered device solutions for your rig, validate with the linked calculator, and keep the OS follow-up steps (fsck/SFC/First Aid) as the last confirmation. If the code recurs after a clean BIOS/driver reset and a memtest pass, isolate the faulty component by swap.

## Bottom Collapsed Extended Long-Tail SEO Q&A

**errSecItemNotFound -25300 on old mac** — Reset SMC/NVRAM (Intel) or shut down fully (Apple Silicon); repaste if overheating.

**errSecItemNotFound -25300 after macos update** — Reinstall the combo/security update, clear caches, rebuild LaunchServices.

**errSecItemNotFound -25300 app damaged cant open** — Re-download the app, or sign it with ad-hoc codesign; do not blanket-disable Gatekeeper.