If the server files are outdated, its very simple to update them. First, if you’re running 2.0.0b (For example) and the server files are 2.0.0a, don’t worry. Updates with an a, b, c, or d are just client updates and do not require a server update.
If your modpack is 1.12.2+, then updating server files is easy. First, delete the mods and config folder out of your server. Then just open your client, go to the mods and config folders, then drag and drop all the mods and configs into the server. Remove the Kinetic Anti-Cheat, and bang… You’re done! Boot your server.
Its a bit more tricky with a 1.7.10 server, as a 1.7.10 server will crash if it sees a clientside mod in its folder. To help you update outdated server files for 1.7.10, all changelogs will let you know what mods are clientside, and what is not. To update your files, just take all the non-clientside mods from that update and add them to your server. Then, like with 1.12.2 just copy the configs over. You’re now done!