Capturing User Profile prevents client-server application from working

I'm a new user evaluating Telerik Test Studio for use with load testing an Excel Plug-In that communicates with a remote application server.

I create a new test project of type "Load Test".

I create a new user profile, selecting  the "Capture all local traffic" option.

I can see general traffic being captured.

When I go to my Excel Plug-In and attempt to login using it, to the the application server, I get an error about the underlying connection being closed. This only happens when I try to record traffic.

Probably something basic I'm doing wrong - maybe related to the application server being connected to using a https connection????

Here is a link to a screencam: https://drive.google.com/open?id=0B5947ZWN_1xULTRlRmc5S1JZOE0

Any help much appreciated

- Matt