I have this error code and don't know what to do UU_400_EB000A9900

[AntoinetteM1]

I have this error code and don't know what to do UU_400_EB000A9900

[VikramTheGreat]

Hi @AntoinetteM1,

Welcome to the HP Support Community.
 

Thank you for posting your query. I will be glad to help you.

I know how confusing it can be when your HP printer throws up an unfamiliar error like UU_400_EB000A9900, especially when you're in the middle of something important. You're not alone, and I’m here to help you through this with clarity and care.

What Does Error Code UU_400_EB000A9900 Mean?

This error typically appears during sign-in or Instant Ink enrollment via the HP Smart app. It’s part of a group of errors that indicate a problem with account authentication or printer setup.

HP describes this as a “Something unexpected happened” error, which may be caused by:

• Incorrect or outdated HP Smart account credentials.
• A printer that’s not properly connected to the internet.
• A mismatch between your printer and HP Instant Ink eligibility

 Steps to Fix the Error

1. Restart Everything

• Power off your printer and unplug it for 30 seconds.
• Restart your computer or mobile device.
• Reconnect the printer and try signing in again via the HP Smart app.

2. Update the HP Smart App

• Make sure you’re using the latest version of the HP Smart app.
• You can download or update it from 123.hp.com - Printer setup from the HP® Official site.

3. Re-add Your Printer

• Open the HP Smart app.
• Remove the printer from your account (if listed).
• Click “Add Printer” and follow the setup instructions.
• Ensure your printer is connected to the same Wi-Fi network as your device.

4. Check Instant Ink Eligibility

• Some printers may not be eligible for Instant Ink in certain regions.
• If your printer was previously enrolled and moved to a new country, this could trigger the error

I hope this helps.

Take care and have an amazing day!
 

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Regards,

VikramTheGreat