A Forge 1.7.10 mod that warns/kicks players connecting with the wrong modpack version.

Mismatched versions show the red X in the server list and a warning before joining.

Servers can be configured to reject mismatched or missing versions, which is enabled by default.

Screenshots

Server list	Join warning	Connection rejected

Setup

1. Download the latest jar and it's accompanying UniMixins dependency.
2. Put both of them in the mods folders of the client and server.
3. Launch each once to generate config/modpackversionchecker.cfg.
4. Set the same pack version on both sides, then restart. Include the config with your modpack releases.

Configuration

general {
    B:kickOnVersionMismatch=true
    S:version=1.0.0
}

• version: your modpack version. Use the same non-empty string on both sides.
• kickOnVersionMismatch: set to false on the server to allow mismatched clients. Client warnings still appear.