The Designer Error window is a special window that provides specific information in the event that a window or report structure could not be loaded for any reason.
In the Clarion Win32 Designers, the most likely reason is a missing or incorrect element contained within the referenced structure.
In the Clarion# designers, the most likely cause is a missing component or declaration in the Clarion# project source.
Usually, the information presented will refer you to a precise line in the source from where the problem originated.