Frequently Asked Question
How do I fix a Synology Drive SSL certificate warning without losing my sync tasks?
ACE SUPPORT · SYNOLOGY
A certificate warning usually needs a server identity, validity or certificate-assignment check. It does not mean that the files must be deleted or the sync task rebuilt. Verify the NAS and certificate before trusting a changed connection.
Applies to
Synology Drive Client, Drive ShareSync and Drive mobile connections to DSM. Domain-name connections, private IP connections and self-signed certificates have different trust requirements.
Before you begin
Do not routinely disable SSL verification, delete a sync database or reconnect to an unverified server. Never publish private keys, passwords or diagnostic logs in a public forum.
Work through these checks
- Record the exact message and the server address saved in the affected task. Check whether the warning began after a certificate renewal, server-name change or NAS migration. Keep local and server copies of important unsynced files before altering the connection.
- Ask the administrator to verify that the address resolves to the intended NAS. Compare the address with the certificate's covered names, validity period and issuer. An IP address generally will not match a certificate issued only for a hostname.
- On DSM, open Control Panel > Security > Certificate. Check the intended valid certificate and its assignment to Synology Drive Server. A working certificate for the DSM web portal does not prove Drive is using that same certificate.
- For a domain connection, renew or install the correct certificate and any required intermediate certificate. Use the approved hostname consistently. Follow the organisation's existing network route; fixing a certificate does not automatically require opening additional ports.
- Return to the existing Drive connection and retry after the server configuration is corrected. Accept a changed certificate only when the administrator has independently confirmed that it is the expected NAS certificate. Keep the original task and file copies while testing.
Confirm the result
Confirm the warning clears and the intended task resumes. Create a harmless test file, check it reaches the other side and reopen it. Merely dismissing a warning does not verify a completed sync.
When to contact us
If the correct certificate still fails, provide the client and server versions, warning text, certificate dates and connection method to our Support Specialist. Share certificate and diagnostic details privately.
Updated 250103