I tested your bot Serenity, and its seems its scripts have been corrupted somehow.
Part of the state machine for the bootstrap scripts was forgotten or deleted, which was causing an error in its script processing.
I'm not sure how that could occur, as the scripts are pinned, so should not be forgotten. Did you accidentally unpin or delete some data related to the scripts? Note the scripts are stored in the bot's knowledge base like any other data, so you need to be careful if you edit knowledge directly from the Knowledge page.
To fix your bot, click Rebootstrap from the Script page, then re-import the alice script you had added. You will need to cleanup the memory in between these, as your bot's memory is already maxed out. Do you want me to fix it for you? Or you could just create a new bot.
You may also want to disable learning in your bot so it does not learn from you when testing it. You can use correction to correct its replies, or train it from Training or Chat Logs.