What is causing error code 4000?

Hello KansasBird,

Thanks for using Apple Support Communities. It's our understanding that you're seeing error 4000 when trying to update your iPhone with a computer. We're happy to help.

If you've followed all steps in the resource you came from, we recommend testing the issue with a different cable. If the issue persists, try updating with a different computer.

Let us know the results. Please include additional error messages and any other troubleshooting steps that you may have tried.

Have a great day!

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