SSL / TLSChrome · Edge
ERR_SSL_PROTOCOL_ERRORSSL Protocol Error
The SSL/TLS handshake failed. The browser and server couldn't agree on an encryption protocol version or cipher suite.
Why this happens
- The server uses an old, deprecated TLS version (SSLv3, TLS 1.0)
- A misconfigured SSL certificate or key mismatch on the server
- Antivirus or firewall intercepting HTTPS traffic
- Corrupted SSL state in your browser
- The server's certificate chain is incomplete
How to fix it
- 1
Clear your browser's SSL state: Settings → Privacy → Clear browsing data (cached images)
- 2
Temporarily disable your antivirus's HTTPS scanning feature
- 3
Try a different browser to rule out a browser-specific SSL issue
- 4
Check if the site's certificate is valid using an SSL checker
- 5
If you manage the site, upgrade to TLS 1.2+ and verify your certificate chain
Diagnose it faster
Use our free tools to check whether the issue is on your end or the server's: