Synology NAS Error Code 56: How to Fix It

Easy 10-15 minutes Medium Severity Verified June 2026
Summarize with ChatGPTSummarize with ClaudeSummarize with Perplexity Add as Preferred Source on Google
Error Code
56
Brand
Synology
Product Type
nas
Severity
Medium
DIY Difficulty
Easy
Estimated Fix Time
10-15 minutes
Error code 56 on your Synology NAS means the SSL certificate used by DSM has expired. This can cause security warnings and block certain services. The fix involves renewing the certificate via DSM Control Panel or using Let's Encrypt.
Ad

Tools You'll Need

How to Fix Error Code 56

  1. Log into DSM

  2. Open Control Panel

  3. Navigate to Security > Certificate

  4. Identify the Expired Certificate

  5. Renew the Certificate

    Ensure your Synology NAS has internet access to renew via Let's Encrypt.

  6. Apply the New Certificate

  7. Restart DSM Services

    Restarting services may temporarily disconnect active connections.
Ad

When to Call a Professional

If you cannot log into DSM because the certificate error prevents access, you may need to reset the SSL certificate via SSH or contact Synology support. Also, if you don't have a domain name for Let's Encrypt, you may need to purchase one or import a paid certificate.

Frequently Asked Questions

What causes Synology error code 56?
Error code 56 appears when the SSL certificate used by DSM has expired, causing security warnings and potential service disruption.
Can I still access my Synology NAS if error 56 appears?
Yes, you can still access DSM by accepting the security warning in your browser, but it is not recommended to ignore expired certificates for long.
Do I need a domain name to fix error 56?
Not necessarily. You can import a custom certificate from a Certificate Authority, but the easiest method (Let's Encrypt) requires a valid domain name.
How long does it take to renew the SSL certificate?
Renewing via Let's Encrypt typically takes a few minutes. Importing a custom certificate may take longer depending on the CA.
Will renewing the certificate affect my data?
No, renewing the SSL certificate does not affect your stored data. It only updates the encryption key for secure connections.

Related Error Codes