This message is generated if the languages selection of the current script contains a language which no longer exists in your database (ie. it was most likely deleted).
You will not be able to generate a diary until this message is addressed.
Solution
•Edit the List of Languages: Use this solution to select another language, instead of the one being referred to by the present message.
•Open the Tokens and Translations Manager: Use this solution to go into the tokens and translations manager and modify the options of the language being referred to by the present message.
Topic 180380, last updated on 22-Mar-2021