Failed to connect to SMP Onboarding Service in Appbuilder

I have been working with Appbuilder since 2 months ,Earlier I was able to make connections between appbuilder and SMP cloud SP02v.

But recentlly on retreving th e connection profile ,I am getting Error Message as:

Failed to connect to SMP Onboarding Service. The error message is:

{}

Earlier whenever I got connection issues the braces were not empty but now the error comes with empty braces.

If anyone could help me .what could be the reason behind the connection failure.