How do i force user who use my modpack to update to my newest version

[CitycraftSMP]

Ho do i force users who use my modpack to update to a new version?

[dwwojcik]

You can't.* It's entirely optional to update.

If for whatever reason they reset the pack or delete the folder, their only option to redownload is the latest.

*As far as I know, but I'm pretty sure.

[Neowulf]

Ho do i force users who use my modpack to update to a new version?

Are you talking about users not doing updates? Because that you have no control over and will never have the ability to force anything.

Or are you talking about you change the pack but the users don't get automated update messages? Because that has to do with the modpack version field.