Protocol4

Protocol4 is a server related 1.7.10 client to 1.7.5 servers support Liteloader mod.







Github Description:

Minecraft mod that links 1.7.10 clients to 1.7.5 servers

Protocol4 is a bridge mod between 1.7.10 clients (protocol 5) to 1.7.2/4/5 servers (protocol 4). To join a protocol 4 server, open the multiplayer menu and click the [1.7.10] button on the bottom of the screen. It will change to 1.7.5 and refresh the server list. If you can't remember what versions are compatible with others, the button text will cycle through the supported versions while hovered.

Known issues
Owned skulls appear as Steve. This was to fix a crash while rendering them.

Minecraft Forum Description:

Do you play on a server that's still on 1.7.5? Do you want all the new features and fixes of 1.7.10, but still want to play on the server? Then this is the mod for you.

Simply put, this mod allows your 1.7.10 client to connect to an outdated 1.7.2/4/5 server. I can do this by modifying the packets before they're read and after they're written to make them comply with the set protocol.

How to Install
Install LiteLoader 1.7.10_04

Download the mod and place in mods folder.

Launch Minecraft.

How to Use
This is a mostly background mod, but there is one part that has user interaction. When Minecraft starts up, it will default to 1.7.10 mode. To change this, open the Multiplayer menu and click the new button in the bottom right corner. This will switch to 1.7.5 mode. Click it again to switch back. If you forget what Minecraft versions are supported by a mode, the button text will cycle through the supported versions while hovered. Images of this screen are attached.

After you've selected the desired mode, simply join the server and everything should work as if you were on that version. If you've selected the wrong mode for a server, you will not be able to join.

Download
1.0.2: https://www.dropbox.com/s/x205gjuvc7ou4in/Protocol4-1.0.2.litemod?dl=0

Changelog
1.0.2: Cache profile properties, Gui fixes, fix occasional crash during transforming.

1.0.1: Fix Forge incompatibility

1.0: Initial release

Source
The source is available on my GitHub.