After you replied I tried
1. Deleted related controls added again restarted whole project.
2. Took a panel and loaded layout of sample project (just to check) and added in my project.
in both case it didn't show.
3. I designed a new fresh layout with only 2 controls as in example added in my project, It showed.
Encouraged by this I copied all views from my existing layout to the new layout again it disappeared.
For now i have moved on with normal PB.
To debug this i will have to add views from my layout to working layout(in step 3) one by one and see when it disappears.