I had to google to see what that was - some kind of KDE gadget? It's not useful to me.
Slackware has some SysV compatibility built-in for dumb programs that require it but it's BSD - if you need to fix something, edit Slack's scripts with a text editor and if you need to add something that doesn't really go anywhere else, stick it in /etc/rc.d/rc.local.
As far as how the program should act if you *did want to use it, I don't know - maybe it just doesn't recognize the names, structure, and so on, of Slack? No idea really.