How get details from validation team about an error while testing my application

The validation team reported to me an error on my outlook web-addin. I cannot reproduce the error, then I don't know how to fix it. Is it possible to contact the validation team to get some details about the error?

My Add-In has a button that generate a file (with a specific extension: .j2s) and start the download of it. The file is generated by linking (with target _blank) an ashx handle (generate.ashx). The validation team reported to me an error like "The page cannot be reached". But, the url is right and reacheable.

My suspect is that the file extension can be blocked by some security policy...

I've added the extension in my web.config:

<system.webServer>
    <staticContent>
        <mimeMap fileExtension=".j2s" mimeType="application/j2s" />
    </staticContent>
</system.webServer>

I need to know in which conditions the validation team obtained the issue, if not I don't know how to fix. In the validation test results document they say:

• Contact us: We can help you resolve your validation issues more quickly.

But, how can I contact them?

Thank you