Hello ,
Thank you for your reply.
The MP builder is at the latest version. 1.1.0.

I actually have 3 API versions for Veeam. But this is not an issue with the Veeam API. It is responsive. I've tried this connection from a linux box, from Windows using PowerShell and from Postman. All are successful.

This is the Content-Type:

The 3rd party blog is referenced by VMware documentation - Management Pack Builder - VMware Technology Network VMTN
The builder wants to parse the body as JSON and it fails. It even does so when I enter valid JSON. I tried all possible combinations, but it just send the body as raw string.

This is the API log.

The same call done from Postman has this in the API log:

I do not understand how should I write this bit, in order for the parser to not error out.

Thank you,
Paul