Must admit, am baffled.
Slimjet for Linux ships with two scripts xdg-settings and xdg-mime, which appear to be very outdated versions of those provided in most distros by the xdg-utils package.
Does Slimjet use any system-installed versions of xdg-settings and xdg-mime before trying to use its own versions?
These 'official' scripts are grindingly slow at the best of times ... if Slimjet could avoid using them, period, I'd be delighted!