A conversation could not be created because the Conversations user associated to the given Frontline user is a participant in too many conversations.
Possible Causes
The Conversations user associated to the given Frontline user attempted to create a conversation and exceeded the Conversations service's maximum user conversations limit.
Possible Solutions
If you frequently exceed the user conversations limit for the Frontline Conversations service, you may want to consider raising your user conversations limit.
Read more about Conversations API user conversations limits in our docs.
In order to request a limit increase, please contact customer support.
Ask the Frontline user to close or transfer some of their active conversations.
Delete conversations the user is a participant in.