https://bugs.winehq.org/show_bug.cgi?id=27580
--- Comment #7 from Rosanne DiMesio dimesio@earthlink.net --- I have the same version of Krusader as you; my KDE version is 4.11.5.
Check the properties of ~/.local/share/wine-extension-txt.desktop. In particular, what is in the "Command" field on the Applications tab?