Do you have a Dataset in your project I've heard of this happening with dataset files, but usually once you close and re-open the dataset designer it goes away.
Are there any clues to what file the element is missing from What is the root element of the project file you have now
Error: "Root element is missing" on open project
Dark Yoghurt
Do you have a Dataset in your project I've heard of this happening with dataset files, but usually once you close and re-open the dataset designer it goes away.
Are there any clues to what file the element is missing from What is the root element of the project file you have now