Facing an issue with Flash builder 4.7

Hi,

Facing an issue with Flash builder 4.7:

Flash builder 4.7 gives below error when project export to release build

Error: Flash builder could not publish the project:null

I'm able to create release build  with same source file in 4.6 version but only 4.7 gives problem

The builder 4.7 version uses new workspace.

How to solve this?

Thanks,

Imgsrn