PDF file is not generating for Billing Document for Invoice

Hi all,

We have upgraded our system into ECC6.0 from 4.7 version. During our Testing time, we have found the following Bug:

Bug: Not possible to get output in pdf format for Invoice type(TR code: VF02) except for all it is generating PDF output.

Can anybody help me out to find the route cause for this problem.

Regards,

Murali