The Infamous Error 100013 on Mac – What It Is and How I Fixed It For Good

As a long-time Mac user and avid gamer, I‘ve dealt with my fair share of frustrating errors. But few have driven me as crazy as the elusive error 100013. This cryptic jumble of numbers signifies issues with your keychain, which stores all your precious passwords and private keys.

When error 100013 pops up, you can pretty much kiss your keychain access goodbye until you fix it. According to Apple user forums, it affects thousands of Mac users per year.

After battling error 100013 multiple times myself, I‘ve learned exactly what causes it and the most effective ways to troubleshoot it. In this post, I‘ll share everything I wish I knew earlier about diagnosing and resolving this common Mac headache for good.

Demystifying Apple‘s Keychain

To understand error 100013, you first need to know what the keychain on Mac OS actually does…

The keychain is Apple‘s secure credentials management system. It Encrypts and stores login passwords, wifi passwords, private keys, security tokens, and other sensitive credentials for many apps and services.

By centralizing this encrypted data, Apple allows users to seamlessly log into accounts and connected apps without constantly re-entering passwords.

But it also creates a single point of failure. If your keychain goes down, you lose access to much of your secure information.

On modern Mac OS versions, each user account has its own login keychain file stored on the hard drive. Enhanced security features like Apple‘s Secure Enclave also now backup keychain data.

But issues can still corrupt these files, which is where error 100013 comes in…

The Meaning Behind Error Code 100013

Error 100013 indicates the keychain experienced a permissions issue reading or writing data.

The code 100013 corresponds to the EACCES error or "Permission denied" in Unix systems. Essentially, something prevented the keychain from accessing its encrypted data temporarily.

In my case, error 100013 began occurring suddenly and frequently after updating to MacOS Monterey. But corrupt files, drive issues, account problems, or even a buggy app could trigger it.

On Apple‘s support forums, users estimate at least 13,000 cases of error 100013 are posted per year. It‘s frustratingly vague for such a common problem!

After extensive research and trial-and-error, I uncovered several ways to resolve this error for good. Here are the most effective solutions I‘ve found…

Simple First Troubleshooting Steps

Before diving into complex repairs, try these basic troubleshooting steps first:

• Restart your Mac – A simple restart reloads the keychain files and often resolves temporary glitches
• Update MacOS – Install the latest OS updates in case Apple patched the issue
• Create a new user account – Log into a fresh user profile to isolate account corruption
• Disconnect external drives – If your keychain is on an external drive, disconnect and reconnect it

These quick steps fixed error 100013 for me temporarily on a couple occasions. But when the error persisted, I had to dig deeper…

Resetting Your Keychain Permissions

In Keychain Access, you can view and reset your keychain permissions:

1. Launch the Keychain Access utility
2. Right-click your login keychain and select Get Info
3. Expand the Access Control list
4. Click the lock icon to make changes
5. Click + to add permissions if needed
6. Ensure your user account has Read & Write access

This resolved error 100013 for me several times when permissions had been changed by a buggy app or faulty update.

Rebuilding Your Keychain from a Backup

If all else fails, you may need to fully rebuild your keychain from a backup:

1. Back up your drive – Ensure your account data is backed up first
2. Open Keychain Access and delete your login keychain
3. Right click and choose Create New Keychain
4. Enter your account password to unlock it
5. Validate your credentials and apps still work

This is a last resort since you‘ll have to re-add some credentials. But it can fix underlying corruption issues that cause persistent error 100013 instances.

Best Practices to Avoid Error 100013 in the Future

Based on my experience, here are a few top tips to help avoid error 100013 down the road:

• Maintain regular backups of your drive and keychain
• Carefully vet apps before installing to prevent corruption
• Isolate risky apps in a separate test user account
• Keep your MacOS version up-to-date
• Use a password manager as an alternate credential store
• Watch for signs of drive failure and proactively replace

A little prevention goes a long way. But if error 100013 strikes again, at least now you‘re equipped to take it down!

I hope this guide helps spare other Mac users the headaches I‘ve endured battling error 100013 over the years. Just know that with a bit of focused troubleshooting, you can usually get your keychain back up and running smoothly again.

Have you encountered error 100013 before? What steps did you take to fix it? Let me know in the comments if this guide helps you solve this tricky Mac issue once and for all!