Do you need same forge mod on server AND client?

[gardengnomer]

Hello!

This if my first post here. I got interested in Forge because of its ability to add new blocks to the game.

However, I was under the impression that making a server-side mod would be sufficient for this.

After struggling through some tutorials, I finally managed to make a mod and got it to run on my server, only to have my client rejected with

 

Network Disconnect: Mod rejections [FMLMod:tutorial{1.0.0}]

 

So, do I need all my clients to have the same mods installed?, or could this be caused by some other error e.g. in my build.gradle file?

[gardengnomer]

Update: Checked by installing same mod client side.

Then everything works, but this is not what I had been hoping for.

[Choonster]

Whether or not each side needs a Forge mod installed depends on what the mod does.

 

If it adds a new Block or Item, both the client and server must have the mod installed.

 

If it adds a new server-side command, only the server needs to have the mod installed (though the client will also need it installed if you want to use any non-vanilla localisations).

 

If it changes client-side things like rendering, only the client needs to have the mod installed.

 

Set @Mod#clientSideOnly or @Mod#serverSideOnly to true if the mod is client-only or server-only to prevent it from being loaded on the opposite physical side. Set @Mod#acceptableRemoteVersions to "*" (i.e. accept any version, including none) if the mod is only required on one side.

 

Edit: acceptableRemoteVersions, not acceptedMinecraftVersions.

Edited June 3, 2017 by Choonster

[gardengnomer]

Thankyou! It is so nice to have a definate answer. I was getting physically tired from juggling a bunch of Maybes and half-understood web guides in my brain!

 

[Draco18s]

Blocks need to exist on both sides because the server needs to track it and the client needs to render it! 

[jeffryfisher]

12 hours ago, gardengnomer said:

I got interested in Forge because of its ability to add new blocks to the game.

However, I was under the impression that making a server-side mod would be sufficient

Think about it for a moment... The client displays things. How could it display a new block known only to the server? Servers do not distribute renderers and their textures.

 

In fact, with graphics-heavy mods, it is possible to make a server-only version of a mod by removing its assets folder before compiling it. Indeed, this is what I do for my paintings mod (shrinking the server version from megabytes down to 45k).