Error in webi report - ORA-06502

Dear All,

I have create an object in Universe "description" , I am using this object in WEBI report.

When I run the WEBI report I am getting below error:

Database error occurred :the databasr error text is ORA-06502: PL/SQL: numeric or value error: character string buffer too small

ORA-06512: at line 1 . (Error: WIS 10901)

This object is working fine in Dev and Quality.

But it is getting above error in the Prod environment in WEBI report.

Actually i think its this "description" object which is the reason

dbms_lob.substr( xyz.DESCRIPTION, 4000, 1 )

Any help is highly appreciated