After some changes on one form in our new multilanguage application we experienced very strange behaviour on UI - while creating new doc using that form, when the user triggered in any way uidoc.Refresh, the form fields and labels disappeared (like blank form) and sometimes (not always) we got the error message “Due to an error, this paragraph cannot be displayed” in status bar. This problem occured only on newly created doc, was not reproducible on existing docs. We spent hours to analyze the form and find the cause by deleting fields, buttons, hide-whens and tables row by row. Finally we found the reason of this voodoo - the main table has programatically switched tabs and the controlling field had default value @ThisValue. It means that on new doc it has value of empty string. We would never realize that empty string value in tab-controlling field can prevent the whole form from displaying on UI.
Hope this post helps and saves time to others affected by same problem. At least we found only one IBM technote on this error message with different cause.