Mashup is giving blank screen on running it or navigating through another Page

Hi,

I have a mashup which was working fine till yesterday. Today morning when open that to view it has given blank screen. I have assigned that to a navigation widget as model popup, even with this it's giving blank screen.  design time there is no issue it seems everything is good.

Can anyone suggest me what can be done to work the screen/Mashup as normal.