Solved: How do I fix OpenSea “Unknown Ethereum address” authentication error

Problem Symptom

I keep seeing a red bar with error “Unknown Ethereum address” after login OpenSea. The account page showing error 404. When I click on wallet, I noticed a weird ETH address that is different from my Coinbase account. Some users reported the same error when trying to sell NFT even after logging out and logging back OpenSea.

The detailed error message is as below:

Unknown Ethereum address

Follow the below solution steps to resolve OpenSea “Unknown Ethereum address” error issue.

Content Summary

Potential Causes
Pre-check
Solution 1: Re-login OpenSea
Solution 2: Re-connect Wallet
Solution 3: Disable or remove Ad-Blocker plugin
Solution 4: Use incognito mode or InPrivate Window without plugin
Solution 5: Use Microsoft Edge
Solution 6: Use phone
Solution 7: Delete temporary files and browser cache

Potential Causes

• You have typed the wrong Ethereum address.
• Internet connection not stable.
• OpenSea servers may be down.
• Corrupted cache file.

Pre-check

Confirm again you have entered the correct Ethereum address. If you are using MetaMask, make sure you have update your MetaMask app.

Solution 1: Re-login OpenSea

Logout then login back again about 3 to 4 times by scanning QR code and eventually it will be worked.

Solution 2: Re-connect Wallet

In Coinbase app’s setting, disconnect the wallet from OpenSea then reconnect again.

If you are using MetaMask, make sure you have selected Ether as the payment method for your transaction.

Solution 3: Disable or remove Ad-Blocker plugin

In case you have installed Ad-blocker plugin on your system, you need to disable or remove it to make sure OpenSea transactions complete without errors. Either disable it or remove it from the system before the transaction start.

Solution 4: Use incognito mode or InPrivate Window without plugin

Use a clean browser, without any other plugin installed, open in incognito or InPrivate window.

Solution 5: Use Microsoft Edge

Use Microsoft Edge as your default browser to perform the transactions.

Solution 6: Use phone

Use phone to access OpenSea instead of desktop.

Solution 7: Delete temporary files and browser cache

Refer to this page for more detail steps to delete temporary files and browser cache for in Google Chrome, Mozilla Firefox, Internet Explorer, Microsoft Edge, and Opera.