Hi Rahul,
Thank you for your post.
The message is sometimes related to secured StreamSets environments, and internal network configurations. You'll need to open it on an engine you have access to. Your StreamSets administrator should be able to help you.
The message is indicating that your machine has no network route to the engine, or possibly your engine is not configured for TLS.
This documentation describes engine communication [link].
Please open a support ticket if you're still experiencing issues [support link].
I hope this helps.
Best Regards,
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Eric Greisdorf
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