SAP portal 7.4 document viewer

Hi all,

We have in a upgrade process. We transported all portal content from old portal version 7.0 to new portal 7.4.

Also we have updated our backend system ECC from version 7.0 to 7.4

When we call a task from UWL, we can see a information about a invoice. The problem is ocurring when push the button "image" and it open a new window Document viewer but we can't see the document-image.

Please could you help me with this issue?

I dont  know if can be a portal problem or backend problem.

Thanks and best regards

Mónica