I saw the same error as one mentioned in this post aws forum post
Error: Something went wrong, please try again, if your problem persists then please contact the bot's developer. Error occurred at: 2019-10-09T15:58:29.153Z[UTC].
The messenger I was using with Lex integration was working the previous week and nothing new was added to the code base. Does anyone know if there is a recent change to Lex that could cause this?