Header not displayed after file is closed and reopened

Header not displayed after file is closed and reopened

I have created templates that contain in the header my logo and my address (text box). Since today the text box is not displayed anymore. Also for existing documents when I open them the address text box disappears.

I click on the header and hit enter and the text box appears. However when I download the file as pdf or word document the text box is not displayed even so I see it in the document. 

Until today this worked fine. When I open up older documents the same happens.

This is a major issue for me. I can't use writer or docs anymore