Unable to insert an image inside page properties macro

Steps to reproduce:

1) Insert a new page properties macro in a page.
2) Try to insert an image inside it.
3) Click on save or preview.
4) The image will not appear and the following error will appears instead:

Error: The XML content could not be parsed. There is a problem at line 1, column 980. Parser message: Unexpected close tag </xml>; expected </img>. at [row,col {unknown-source}]: [1,980]