I cannot send any message from the appointment popup -
http://prnt.sc/tixlfq and this is the video:
https://screencast-o-matic.com/watch/cYiDlQEfgD
The Buddypress Component is not enabled on your site
Go to wp-admin > Settings > Buddypress and enable this:
http://prntscr.com/tjgl2q
Then save changes
I have enabled it and passed the first scenario. Now, the problem is that the button remains in "Sending...": http://prnt.sc/tjinyk . I have checked the request in Dev Console and it is 200 OK - http://prnt.sc/tjiojn
I also see that there are failed requests in console: http://prnt.sc/tjiou1, http://prnt.sc/tjiowv
I have checked the student profile for messages, but found none: http://prnt.sc/tjirs1
Asked you to share credentials over email. Please do not ping all the issues at once. I will check one by one and after resolving one topic move towards next