i have the same problem.
i start jkdefragGUI 1.12 with defrag 3.34 choose -> analysing only -> the window "color of clustersize" pops up and close immediately with a *beep* and it stopps.
let me now if you need additional information to analyse this.
It would be nice if you report which GUI you are using ..
and if you report your problem to the maker of the GUI instead of posting it onto this forum.
where can i report this GUI problem ?