DRILL-THROUGHT FUNCTIONALITY IN SSRS MOBILE REPORT BASEN ON MDX DATASET

Hi 

I created two seperate report based on cube (MDX).

1. Main 

2. Drillthrough 

When I want to drill main report to second one, I received an error that my report is misconfigured or server is not supported.

But interesting thing is when I prepare the same reports in Report Builder and include in parameter value UniqueName property ([UserName.UniqueName]), it works fine. 

Any Idea where I can set that property in Mobile Report or how can I change my parameter definition in MDX query ??