custome theme problem

Hi experts,

I try to create a custom theme in SAP portal 7.31.5. When I open the SAP tradeshow with elementen ´Classic Framework Page´ and save this theme, with a new name, the  customer_brand_image is not displaying anymore. When I add (upload) a custom image I can see it in the theme editor but when I save the image is disappeard when it´s saved. I can not add a new image.

How can I solve this?

Thanks in advance,

Vo.