I am still having the above issue with 0.8.18. The welcome message will initiate (even when changed in Watson Assistant in IBM Cloud) but messages can not be sent.
Here’s some log messages:
from console:
Error: "Message could not be sent."
value https://chatmetwillem.nl/wp-content/plugins/conversation-watson/app.js?ver=0.8.18:1
from WP:
Event 5d9c3431f1770, 2019-10-08 07:01:05
#8: Watson Assistant response error
Service Unavailable - Zero size object
The server is temporarily unable to service your request. Please try again
later.
Reference #15.d7f31502.1570518065.1030597
No messages are sent to IBM, as the analytics tab doesn’t list them.