This document tries to help you with common problems. If you would rather ask a human or this document does not help you come join #matrix-registration-bot:hyteck.de. If you believe that you found a bug please report it on GitHub.
This indicates that the bot is not working properly. Check if the bot is still running and what the logs say. Usually
this is a misconfiguration of the bot in config.yml.
Check if the chat with the bot is encrypted. The bot does not yet support encryption, therefore it will not work in such a room. You can circumvent this problem by creating an unencrypted room and invite the bot to it.
This can happen if you change the bot user. If this is the case, deleting the session.txt and restarting the bot will help.
The session.txt is located in the working directory of the bot. For the docker deployment you can run the following
command (make sure to adjust the container name if it is not matrix-bot-matrix-registration-bot).
docker exec -it matrix-bot-matrix-registration-bot rm /data/session.txt