Passing values to subreport in SSRS throwing an error - Data Retrieval failed for the report, please check the log for more details.

I have used CStr and CChar to convert to string in report... but still showing an error...

In the table where I have the parameter values has the datatype varchar and in the cube it has WChar.

I am not sure whether it is with the datatype.

Please advise me on this.