Loopcloud DRUM will contact the standalone Loopcloud application when loading the plugin. Depending on the size of your Loopcloud library, internet speed and other factors, this can either be very quick or take 5 seconds or so. If this takes longer, please make sure the Loopcloud app is in focus (open the window or ALT+TAB until you see the Loopcloud window) then go back to your DAW.
We are aware of an issue with certain OSX machines where this step needs to be taken, but our developers are looking into it.
If you have any further questions about Loopcloud Drum at all please get in touch with our Support Team at firstname.lastname@example.org - we'd be more than happy to help.