Error in BEX report

HI BW guru's.

Iam executing a zreport in BEX, which is showing up all the vales that are there in the cube, except one master data attribute. when I check in master data contents it is having the values in it. But in the BEX all the values for the column shows upo as "ERROR".

can any one explain me what went wrong and what needs to be done in order to display the values of the master data in the query.

Thanks in Advance,

Dilse...

Harish