SIRIS, ALTO, and NAS: Error: Add Agent failed: pairing validation could not be completed



When you try to pair an agent with your Datto appliance, you receive the error message "Add Agent failed: pairing validation could not be completed."


  • Datto Windows Agent
  • ShadowSnap Agent


This can happen when you try to pair a production machine that was previously paired with an old Datto appliance to a new Datto appliance. In this situation, your Datto device needs to contact its offsite monitoring servers to validate the request. If communication with the servers fails, the request will not complete.

For security purposes, a Datto appliance will not pair with a production machine previously paired with another Datto appliance until it receives validation from its monitoring servers that both it and the production machine belong to the same reseller.


1. Make sure that the Datto appliance has unrestricted to the Internet addresses specified in the SIRIS, ALTO & DNAS Networking And Bandwidth Requirements, and that all communication requirements defined in the following articles are met between the production machine and the Datto appliance:

2. Attempt to pair the agent again. If you are still experiencing difficulty, contact Datto Technical Support for further assistance.

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