Missing Mods Checker
Ensures the user always has core mods for the modpack, and allows prompting them to download optional mods on startup
I don't know my version or loader

Missing Mods Checker is a simple utility mod for modpack devs that hooks into the pre-loading process for Forge & Fabric to check if any dependencies are missing before the game loads. If any are found to be missing, a window will pop up prompting the user to download them before restarting.


This utility mod can serve multiple purposes:
- Prevent important mods from being accidentally or deliberately removed
- Enforce exact versions of mods, to prevent accidental end-user updates
- Prompt to download mods that are only available on certain platforms
- Allow users to download optional mods the first time the game starts up
Whatever the reason mods are found to be missing, the mod will open up a simple Java Swing window with a list of all missing mods. The user can click "download," which will open the link specified in the config file in their browser. To make things easier, there is a button that opens the mods folder directly.

You can configure the mod by editing missing_mods_checker.json in your modpack's config folder, and adding in entries for each mod. The dependency scanning supports regex for filenames, so you can specify exact versions, or a regex match for anything you would like.
- Edition: Minecraft Java
- File type: .jar
- Minecraft versions listed: 1.20.1, 1.20, 1.21.1
- How to install: Install the matching mod loader (Forge, Fabric or NeoForge) for your Minecraft version. → Download the .jar. → Put it in the .minecraft/mods folder and launch that loader profile.
- Where to get it: Opens on CurseForge — not every file is mirrored on our own servers.
Install steps are the general flow for this file type — How to install Minecraft Java mods & modpacks walks through it step by step.
- Ships as missingmodschecker-neoforge-1.0.1-1.21.1.jar — drop this file into the mods folder
- Download size: 398 KB
- Download link checked 23 Aug 2026 — working
These come from our own check of the pack file, not from the source page.