An issue testing with SSL in Postman

This post deals with a problem I ran into while testing my .NET Core web APIs using the popular tool Postman, and what I did to get around it. Warning: What I describe here is a workaround for one’s local dev environment only.

The problem

I was testing my API with HTTPS on my , where I have a self-signed certificate such that it produces the following page when I browse to it in Chrome:

Your connection is not private

Whenever I tried to submit a request to one of my endpoints, e.g. a simple GET request, Postman would report an error like this:

Could not get any response

The solution

I discovered a more detailed error message by choosing “Show Postman Console” from the “View” menu in Postman:

Error: unable to verify the first certificate

This appears to be related to issue #2214 on Postman Support. To get around this, I disabled “SSL certification verification” the “General” tab of the “Settings” window:

SSL certificate verification

Ever since changing this setting, I have been able to submit requests normally.

Used for this article

  • Postman 7.14.0