database connection issues

HI

I am using Web Intelligence Rich Clint 12.1.0.882. I am facing an problem while creating a report it return back error as shown in figure the report was working I do'nt know if I do an mistake which could be the reason make the application return this error

can any body help me to solve this issue. I have oracle 10G database as backend. I can connect to the database from sqlplus.