hi i am having threading issues in my vsto project

    // code for function
var threadUpdate = new Thread(_fun){IsBackgroud = true};
threadUpdate.Start();
threadList.add(threadUpdate);

// code for progressbar
Progressbar pb = new Prgressbar(){Title =@"abc"}
pb.Show()

it was working in perfect condition before i add wpf progress bar. as the plugin has been running as single thread

can i ask how can running multi threading in outlook

thanks