Error when running pbiviz start-command after installing powerbi-visuals-api v.3.5.1

Hi,

I am doing some tests with the latest version of the powerbi-visuals-api, version 3.5.1.

I updated my packages also running "npm update"

So far so good.

However when I start the custom visual using the command "pbiviz start"

I do get an error (white letters, red background) without further information (see attached screenshot)

After this error the visual is compiled without any errors and I still can use it. I am just wondering what this error-message means.

In fact I have two questions:

1.  Why does the [email protected] install every time I start the visual with "pbiviz start"?
2.  Why do I get this "error"?

Let me know if you need more information.

Thanks in advance.

Paul