I have aproblem with sub report in report viewer

First I designed Subreport report and add paramter to it .

Then i designed another report and add a subreport and Right click in the subreport and choose parameter and assign my paramter to the value i want

Now all think is OK But i still have a problem with subreport I have error message "Error: Subreport could not be shown."

Even I include all report and Sub Report in list .

All Thing is Ok but i still have a problem ???????