They updated the pack.mcmeta to have an updated asset format. In the new format the capitalization of the name of the lang files has changes. So with recent versions so it should now be all lower case. Like en_us.lang instead of en_US.lang.
Did you change the item registration? The lang files should still work as long as you registered them with the exactly matching registry name, that the lang file is named correctly and in the correct asset location and that the lang file has the exact key and no other mistakes like (wrong capitalization or a space after the = sign).
I noticed that your assets directory says assets.wi. Is "wi" your mod ID? I think that might be too short. I can't remember but I think there is a minimum length and some other things now enforced for modid.
So I've updated from 1.11.2 to 1.12.2. In 1.11 the names of the items where displayed correctly... now in 1.12 it just says tile.blockname.name
They updated the pack.mcmeta to have an updated asset format. In the new format the capitalization of the name of the lang files has changes. So with recent versions so it should now be all lower case. Like en_us.lang instead of en_US.lang.
Already did that
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Did you change the item registration? The lang files should still work as long as you registered them with the exactly matching registry name, that the lang file is named correctly and in the correct asset location and that the lang file has the exact key and no other mistakes like (wrong capitalization or a space after the = sign).
I noticed that your assets directory says assets.wi. Is "wi" your mod ID? I think that might be too short. I can't remember but I think there is a minimum length and some other things now enforced for modid.