When rusermanager is minimized, I am not able to maximize or open it. The icon is in my task bar, but clicking on it does not open it.
You can hover over the rUserManager icon on taskbar, when you see the small window, right click on the window and click Maximize.
You can also open Task Manager. On the processes tab, expand the Automai_RdpManager tree, and right-click on rUserManager then click on Bring to front.