How you can make your Resource Pack / Texture Pack 1.12.2 compatible
Minecraft version 1.12.2, 1.12 came with awesome new features but caused most 1.10, 1.9 and 1.8 Texture Packs/Resource Packs to become incompatible. However, we still recommend updating the game to 1.12.2. Below we'll provide you a full guide on how to make your old 1.10.2/1.10, 1.9 Texture Packs 1.12 compatible! different mcmeta file, new models, ... Do you want to make your 1.7/1.8 Resource Pack 1.9 compatible? Then you should have a look at our Convert 1.8 Resource Pack to 1.9 Thread. we will show you how to update an old Pack to 1.9. 1.12 Texture Packs can be found here: Minecraft 1.12.2/1.12 Resource Packs. This guide also works for Minecraft 1.11.2/1.11.
Converting an old Resource Pack to Minecraft 1.12.2, 1.12, 1.11
Step 1: Open your resource pack / texture pack with WinRar or 7zip to get access to its internal files.
Step 2: Open "pack.mcmeta" in a text editor (We recommend to use Notepad++ to do that. You can download Notepad++ here: Notepad++)
How to make your Resource Pack 1.12/1.12.2 compatible
Step 3: Change your pack.mcmeta to:
"description": "1.12 Resource Pack"
That's the pack's "description".
For all versions before 1.9 the "pack_format" number needs to be "1". For Minecraft 1.9 and 1.10 you should use number "2" to make your pack compatible. 1.11/1.12 Texture Packs need number "3" to be there. If you want to make your pack 1.9 compatible you should check out this guide: Convert a 1.8 resource pack to 1.9.
Step 4: Run Minecraft 1.12.2/1.12 and look for the Texture Pack / Resource Pack. If it doesn't show "incompatible" you can check if the pack is really fully 1.12.2/1.12 compatible!
That's how to use Minecraft 1.7/1.8 Resource Packs on version 1.12.2/1.12.
1.12.2 compatible Resource Pack Faithful 32x32