Wrong display of Stack boxes in Editor

Since some days the blue borders of the BOXES of the Stacks in the editor have become white.
The blue label, that indicates the kind of the stack, doesn’t appear anymore.
Into the editor I have only white squares and they are without labels.
What can have about you happened?
I use Foundation.

Thanks a lot to all

check what view mode you are in, at top of the edit window:


Thanks a lot Doug.
It w!orked!

My mistake… how it behave an idiot like me…

Thanks Doug!!!