Redcakes

So I made a server, uploaded the custom resource pack, and some players are having an issue where when they click "Yes" when it prompts to download the pack the pack does not work. How can I make it so it prompts the players again? Restarting the server did not work and neither did rejoining.

The Dangerous Caves plugin is now outdated and has been better optimized in the sequel. Here's the link: https://www.spigotmc.org/resources/dangerous-caves-2-make-your-caves-scary-1-12-2-1-16-3.76212/