Dark blue on dark, almost unreadable link on Export/Save dialog.
In GIMP, if you select "save as" and set the suffix to anything other than the approved one (".odt"?), you get a message telling you that you must select "export" instead of "save as." It would be a lot more friendly to ask, "did you means 'export'?" and allow someone to click, "yes" and then export it.