I'm having a similar issue where this happens every time I open the app, but when I hit retry it always works right away (version 388).
Edit: actually it looks like my error is different - if says "not responding"
Edit 2: seem to be getting both errors now - the "no community" error on start up, so I have to go the sidebar and choose Frontpage, and then it says "not responding" after 10 seconds but works when I hit Retry.