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HubSpot Sales for Outlook install error: "Customized functionality in this application will not work..."

Last updated: June 20, 2017

Available For:

Marketing: N/A
Sales: Free, Professional

When attempting to install HubSpot Sales, you may encounter a "Customized functionality in this application will not work because the certificate used to sign the deployment manifest for Sidekick for Outlook or its location is not trusted" error message.


  • Open Internet Explorer.
  • Click the settings gear at the top right of the window and select Internet Options.
  • Click the Security tab. 
  • Click Trusted Sites.
  • Click Sites and add as a trusted site.
  • Copy and paste this link into Internet Explorer:

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