"Client callback not supported" when consuming a codeunit with run report methods

Using Microsoft Dynamics NAV 2009

I am getting the same error message whenever I debug my C#, which consumes a published web service codeunit. The codeunit takes parameters and designed to run either another codeunit, or a report. When passing parameters to run a codeunit through the C# program, it runs successfully, however if the parameters are changed to run a report instead, I get my error as stated above.

I have researched and removed some problems which I may believe to be the problem. I have removed and function which would cause a dialog box, or I have used GUIALLOWED for them.

I believe the problem may be this. If I try to run a report in the classic client, I am required to select a company before doing this action. This is different for running a codeunit as I am not asked for a company to select. My theory is to add some code into the C# console application, so that before it runs the report, it selects a company beforehand.

I am struggling to solve this error, so any help or advice is welcomed. I am still new to web services.