If you are experiencing problems with SMS conversation, make sure that you can send and receive SMS as expected using CiviCRM's out of the box SMS functionality.
Conversations remaining scheduled¶
A single contact can only carry out a single conversation at a time. New conversations will not start if there is an existing conversation in progress. If a conversation has been abandoned, you will need to manually cancel the conversation.
Note: future versions of this extension, and the new CiviCRM Dialogflow extension (https://docs.civicrm.org/dialogflow/) support automatic abandoning of a conversation after a period of time.
If you are still having difficulties, please file a 'help wanted' issue at https://github.com/3sd/civicrm-sms-conversation/issues.