Applies to: Minecraft Java with Forge, NeoForge or Fabric, on the Gravel Host Panel · Time: about 10 minutes · Difficulty: Beginner
Mods add new blocks, mobs, items and systems to Minecraft. Your server needs a mod loader (Forge, NeoForge or Fabric) before it can run them.
Changing the server software can break an existing world. Download a backup first, or start on a fresh server.

mods folder, then stop it.mods folder and upload the mod .jar files. Create the folder if it is not there.The server starts with no errors in the Console, and you can join from a client that has the same mods.
A mod does not match your loader or Minecraft version, or needs another mod as a dependency. Remove the last mod you added and check its requirements.
Still stuck? Our team is on Discord, or open a ticket from the Billing Panel.