If you or your visitors see the error ERR_SSL_VERSION_OR_CIPHER_MISMATCH when opening your Jimdo website, your browser cannot establish a secure connection to the site. The page will not load and you may see a warning that the connection is not private. This article explains the most common causes and how to fix the issue. Note: This error is almost always related to your domain’s SSL certificate or DNS settings — not your website content. Your site itself is fine. The issue happens at the connection layer between your domain and Jimdo’s servers.
What causes this error?
This error means your browser tried to connect securely (via HTTPS), but the SSL certificate presented by the server is invalid, missing, or blocked.
At Jimdo, this usually happens in one of the following scenarios:
- SSL certificate expired or not issued yet
Common for newly connected or external domains - DNSSEC is active on your domain
Can block certificate validation - Domain was recently transferred
Old SSL data may still be cached - Unsupported SSL protocol (very old browsers)
Affects visitors using outdated devices - AAAA (IPv6) record is set
Jimdo does not support IPv6 - CAA record blocks certificate issuance
Prevents Let’s Encrypt or SSL.com from issuing a certificate
Important: Jimdo uses Let’s Encrypt (and SSL.com as a fallback) to issue SSL certificates. If certificate issuance fails multiple times, it may be temporarily blocked for up to 7 days.
Check which domain is affected
Check where the error appears:
- www.yourdomain.com
- yourdomain.com (without www)
- both versions
This helps identify the root cause.
Reconnect your domain
In many cases, reconnecting your domain fixes the issue by triggering a new SSL certificate.
To reconnect your domain:
- Go to your Jimdo dashboard
- Open Website Builder > Domains
- Disconnect the affected domain
- Reconnect the same domain
- Wait up to 24 hours for SSL and DNS to update
Important: Avoid reconnecting multiple times. Too many failed attempts can temporarily block certificate issuance.
Check for DNSSEC
DNSSEC is a security feature enabled by some registrars. It can block SSL certificate validation.
How to check:
- Go to dnsviz.net
- Enter your domain
- Look for a DS record
If DNSSEC is active:
- Disable DNSSEC at your registrar
- Reconnect your domain in Jimdo
Tip: This is especially common with .CH domains.
Check for AAAA (IPv6) records
Jimdo does not support IPv6. An AAAA record can cause SSL errors.
How to check:
- Go to digwebinterface.com
- Search for your domain with record type AAAA
If present:
- Remove the AAAA record at your registrar
- Wait for DNS changes to update
Check for CAA records
CAA records control which providers can issue SSL certificates.
If your domain blocks Let’s Encrypt or SSL.com, the certificate cannot be created.
To fix:
- Remove the CAA record
- or
- Add: 0 issue "letsencrypt.org"
Check the non www domain
Sometimes the error only appears without www.
Check:
- Open both:
- https://www.yourdomain.com
- https://yourdomain.com
If only the non www version fails:
- Set up a 301 redirect at your registrar from yourdomain.com → www.yourdomain.com
What to do if the issue persists
If the problem continues after following all steps:
- Contact Jimdo Support and include:
- Your domain name
- Where the error appears (www / non www / both)
- Browser and device used
- When the issue started
Frequently asked questions
My website worked before — why does this happen now?
Most often, the SSL certificate expired or could not be renewed. This can happen due to DNS changes or DNSSEC activation. Reconnecting the domain usually fixes it.
Is my website broken?
No. Your website content is not affected. The issue is only with the secure connection.
Why do visitors see the error but I don’t?
You may be seeing a cached version. Try opening your site in an incognito window or another device.
I reconnected the domain but the error is still there
SSL issuance can take up to 24 hours. Wait before trying again.
What is DNSSEC?
DNSSEC is a DNS security feature that can interfere with SSL validation. Disabling it usually resolves the issue.
The error only appears without www — why?
The SSL certificate is usually issued for www. The root domain must redirect correctly to it.
Does this affect external domains?
Yes. Especially if connected via CNAME. DNS configuration must be correct.
Can I check the SSL certificate myself?
Yes. Use tools like: sslshopper.com/ssl-checker.html digwebinterface.com
Can this error be device-specific?
Yes. Very old browsers may not support modern SSL standards. The user should update their browser or operating system.