I don't know if this is a known bug (or not a bug at all), but when exporting (at least through the LaTeX exporter), the exporter often hangs if a paragraph being exported ends with a footnote (such as {{fn1}}). I have found that putting a single space after the second bracket resolved this problem, and allows for the exporter to complete its function. Just a heads up, in case it is something resolvable. Many thanks.