Prosody reporting "Invalid member" for valid circles
Debugging to assist with Calum's work on djangoldp-packages/djangoldp-notification#27 (closed)
djangoldp-packages/djangoldp-notification#27 (comment 39926)
@MattJ receiving unexpected error back from Prosody on this activity: https://api.test1.startinblox.com/admin/djangoldp/activity/707/change/