We all know that best practices dictate you should not make changes to schema on the fly while users are in the database using it. However, there are times when this may not be an option. Currently, FileMaker not allow you to save your changes to a table if it happens to have users with records that are flagged as busy/in use - i.e. uncommitted records. Your only option is to "Try Again". This is fine if you can be patient enough or can contact the user(s) in question to save their changes, but there are times where this is not an option. This is where it would be nice to allow you to "Notify Users" like you can do with FileMaker Server. Why not just user FileMaker server? Well if the users are accessing the files from a locally hosted set of files instead of from FileMaker server, OR you as the developer are not permitted access to the client's filemaker server admin console for some reason, you are stuck.