- Invalid System Time 系统时间与网络时间不同步
- Firewall blocking the website or IP address
- Website could be blacklisted in the Hosts file
- Browser extension blocking the website
- Cookies and Cache not cleared for a long time
Here’s the course of actions to solve SSL Connection Error Chrome ERR_SSL_PROTOCOL_ERROR. If one doesn’t work out, try the next one and so on. Don’t shy away from trying any of these steps because you never know!
1) Disable QUIC Protocol
Disabling QUIC protocol will remove this error permanently from Chrome, here’s how you can do it.
- In your chrome browser URL, type chrome://flags/#enable-quic and hit enter.
- Experimental QUIC protocol would probably have been set as Default. Change it to Disabled.
- Now go to the bottom of the page and click on RELAUNCH NOW
Worked? Great. Didn’t? Try the next one.
2) Remove the Hosts file
- Press Windows + R, type in C:\Windows\System32\drivers\etc & hit enter button
- You will find a file named hosts. Delete it.
Restart Chrome and see whether this has had any effects or not. If not, try the next one!
3) Clear SSL State
If the SSL State is not cleared, it might block SSL connection and cause the SSL Connection Error. Follow the steps below to clear the SSL state.
- Go to Start Menu > Control Panel > Network and Internet > Network and Sharing Center
- Now click on Internet Optionsfrom the bottom-left corner.
- A new Internet Properties window will appear.
- Now move to the Content tab and click on Clear SSL State.
“The SSL cache was successfully cleared” alert should be on your screen.
Again, restart Chrome and check err ssl protocol error if net::ERR_SSL_PROTOCOL_ERROR is still there.
Still nothing? Move on to the next step.
4) Update the System Time
The error could be occurring if the system time is running behind or ahead. Check if your date & time settings are updated.
5) Check Firewall Settings
If the website or its IP address has been blocked by your firewall, chrome will display the error. Check your firewall settings and if you find that website/IP address, quickly remove it.
6) Remove or Disable Extension
Sometimes, the browser extensions could be causing the SSL connection error. It’s hard to know which one is behind it. The best strategy would be removing or disabling extensions one by one.
To view all Chrome Extension, type chrome://extensions/ in the URL bar.
7) Clear Cache and Cookies
Whether you’re getting this error or not, you should clear the cache and cookies of your browser on regular basis. To do so in Chrome, type Ctrl + Shift + Delete and delete your cache and cookies.
We hope you’ve finally got rid of ERR_SSL_PROTOCOL_ERROR Chrome.