When users encounter the ERR_QUIC_PROTOCOL_ERROR in Google Chrome, it can significantly disrupt their access to certain websites. This error is often associated with issues in communication between the client and server via the QUIC (Quick UDP Internet Connections) protocol, which Google developed to accelerate internet browsing. Here are three effective methods to resolve this problem.

1. Disable QUIC Protocol in Google Chrome

The first and most common solution to the ERR_QUIC_PROTOCOL_ERROR is to disable the QUIC protocol directly in the settings of Google Chrome. Here's how to do it:

1. Open Google Chrome and type chrome://flags into the address bar.
2. In the page that opens, type "QUIC" into the search bar.
3. Next to the "Experimental QUIC protocol" setting, click on the dropdown menu and select "Disabled."
4. Restart the browser to apply the changes.

This procedure should usually resolve the ERR_QUIC_PROTOCOL_ERROR by deactivating the use of the QUIC protocol by the Chrome browser.

2. Clear Cache and Cookies in Google Chrome

Another possible cause of the ERR_QUIC_PROTOCOL_ERROR could be corrupt cache or cookies. Clearing these data might help eliminate the error:

1. In the Chrome browser, click on the three dots in the top right corner and select "Settings."
2. In the menu on the left side, click on "Privacy and security" and then "Clear browsing data."
3. Choose the time range for which you want to clear the data, it's recommended to select "All time."
4. Ensure that "Cached images and files" and "Cookies and other site data" are checked.
5. Click on "Clear data."

After clearing this data, restart the browser and check if the problem persists.

3. Update Google Chrome to the Latest Version

Lastly, it's important to ensure that your browser is updated to the latest version. Google regularly releases updates that may contain fixes for various errors, including ERR_QUIC_PROTOCOL_ERROR.

1. Click on the three dots in the top right corner of the browser and select "Help" > "About Google Chrome."
2. The browser will automatically check for available updates and download them if any are found.
3. After the download is complete, restart the browser to apply the update.

By using one or a combination of the methods mentioned above, you can resolve the ERR_QUIC_PROTOCOL_ERROR in Google Chrome and restore access to your favorite websites without further complications.