Change the Global Open Browser Command macro scrip to this

public static void Run(IntPtr windowHandle)
{
string prog = BFS.Web.GetDefaultBrowserExe();
if(!BFS.Application.IsAppRunningByFile(prog)){
BFS.Application.Start(BFS.Web.GetDefaultBrowserExe());
}else{
BFS.Window.Focus(BFS.Application.GetMainWindowByFile(prog));
}
}

the purpose is to prevent multiple windows from opening at the same time due to introduction of tabbed browsing by default for all browsers