Item Tag display

When I first include a Proof tag in my document, I can add text to the proof in the edit window. However, if I save the document and re-open it later, the Proof tag appears as a gray box and I can only see the text by double-clicking on the box. How can the Proof tag with its text be always displayed in the edit window?

Version 5.5 must have the

Version 5.5 must have the proof environment defined in the document preamble.  Compare the preamble for a new document using, for example, the Standard LaTeX Article shell with your document.  Move, as needed, the environment definitions from the shell to your document, then save, close, and reopen your document.  The proof environments should then be visible.  If there is a compile error because the proof environment is defined by a typesetting specification, then see the solution discussed at