Accessing API Spec : Configuration setting missing for $2

[umapadamanna]

When I am trying to view my API spec, getting error "{"error":{"message":"Configuration setting missing for $2"}}".

I am not able to access any of my API spec.

How to resolve this issue? Till yesterday it was working good. I am getting this error suddenly and not able to overcome it.

[wingpoon]

We're seeing the same thing. I've confirmed it with other colleagues with their log in as well.