existing creator form shows blank screen

existing creator form shows blank screen

As of today (although I haven't checked it lately), I get blank screens in the form part (fill-in) of the 2 forms I have created - this happens on Firefox, Chrome and even on internet explorer - i.e. it's not linked with browser type or version.

Edit shows what is should, as well as view - I can even see filled in forms when I edit an item, but still, when <i go to the form page to create an entry, all I get is a blank section of page (left pane shows and work)

Any idea of what's going on?