[DiapDealer]

This affects Linux, as well. It crashes any time a Split at Cursor, or Add Blank HTML file is performed when a file with a .xml extension is the first file in the Book Browser's Text container.

Split at Markers gives the "Cannot split since at least one file may not be an HTML file" warning. Which seems a little odd when the .xml file isn't one that's marked for splitting. But it's preferable to a crash.