Ugdhar

Block drops are done using loot tables, vanilla sources are a good reference, and the Minecraft wiki has a breakdown of the loot table json. Unfortunately the forge docs are out of date, I use Google and the forums search to get info on stuff I tinker with. Lots of vanilla sources and forums reading!

The filenames of your mods suggest that you downloaded them from a repost site, such as 9 minecraft or something. These sites are bad, and often have outdated, and potentially modified versions of these mods, not to mention hosting them without permission. You should delete all of your mods, and go redownload them from curseforge.com. That is the only place I would trust to download mods, aside from the mod developers own site. Visit https://stopmodreposts.org/ for more information and a list of these sites that you should avoid. That being said, 1.12 is no longer supported due to age. See the LTS link at the top of every page for more information on supported versions. TLDR: 1.14.4 or 1.15.2

1.12 is no longer supported due to age. Please update to a modern (1.14.4/1.15.2) version to receive support. More information on supported versions can be found in the LTS link at the top of every page.

Still Java 14. That's your problem then. I don't know how to change it for you, especially if you've run the commands to remove it. That's more of an operating system issue as opposed to a minecraft/forge issue.

Look at the version numbers. You're using Minecraft 1.15.2 You downloaded forge for 1.5.2 Download forge for 1.15.2 and you will have better luck.

You should make your own post, and post logs, code, and screenshots (if the logs and code don't show what you mean)

What are the results of java -version from your terminal?

This is not actually registering stuff, so the order does not matter. This is registering the DeferredRegisters to the event bus, so that it can register your RegistryObjects at the correct time. The only guarantee at this time for registration is that blocks are always first, items second, everything else in an assumed random order afterwards. I have not tried doing anything like you are yet, but I would imagine that it will involve the use of a supplier to provide your entity type.

Then I would guess you still have some java 14 packages on there. I'm fairly sure there's a command in there somewhere to change which version of Java is the default. *edit: did a quick google for "ubuntu java 14 packages", did you remove openjdk-14-jdk? I'm pretty sure JDKs come with JREs as well. If you can't find the command to change the default java version, you could try making sure that package and others aren't lurking.

As far as I know unless things start setting replace to true everything should play nice

Really old versions are no longer supported. Please update to a modern (1.14.4/1.15.2) version to receive support. More information on supported versions can be found in the LTS link at the top of every page.

MadHatAK is correct that you create data/minecraft/tags/blocks in your resources folder and add it there. That's how datapacks override vanilla stuff. Making a walls tag in your mod just creates your own walls tag with only your walls in it.

Really old versions are no longer supported. Please update to a modern (1.14.4/1.15.2) version to receive support. More information on supported versions can be found in the LTS link at the top of every page.

I believe you need to put your walls.json in data/minecraft/tags/blocks

net.minecraft.item.Items

Correct, as there aren't any TEs to attach anything to without a world!

I just checked using forge 1.15.2-31.1.46 and the event fires for me and a breakpoint works. Do any other breakpoints work? Maybe post a debug.log, it might have a clue what's going on.

1.12 is no longer supported due to age. Please update to a modern (1.14.4/1.15.2) version to receive support. More information on supported versions can be found in the LTS link at the top of every page.

net.minecraft.block

Please post your debug.log from the logs folder within the game folder. It should have information to help figure out why you are crashing.

Start a new thread, and post your debug.log as described in the EAQ. There are a million reasons the game can crash at startup, and your problem may not be the same!

Show a 1.15.2 log using Java 8, I do not believe Java 14 is supported. Also, 1.12 is no longer supported due to age.

Yeah, the twitch launcher sucks at installing forge, and that's a likely cause of the error, although I'll be honest and this is a stab in the dark without debug.log. What I've done in the past is download the twitch modpack, close out of the twitch client, make sure I have the exact same version of forge installed the modpack is calling for, then create a new installation in my normal vanilla launcher that points to the modpack folder in twitchs Instances folder. You could try that and see if it makes a difference. Just make sure you install the same version of forge the modpack wants to use, older can be missing things, newer can have breaking changes.

Please post the debug.log from your game directory logs folder. It will give details on what's going on. Unfortunately without it, it's all just blind guesses!

So I've been tinkering with Biomes recently, and I'm wondering if anyone has any insight into the methods used by the biome builder, in regards to what they do/how they affect biomes spawning. Example taken from PlainsBiome: .depth(0.125F) .scale(0.05F) .temperature(0.8F) .downfall(0.4F) .waterColor(4159204) .waterFogColor(329011) .parent((String)null)); Looking at code and what different biomes set these values to, I've come up with some guesses for a couple. depth - Oceans have -1.0, Mountains have 1.0, Rivers are -0.5, with other biomes being between 0 and 0.2, so based on what elevations you want a biome to show up in would affect what you put for this value. scale - not sure temperature - Desert is 2.0, and "Frozen" biomes are 0, and other biomes seem to be just under 1.0, which I would imagine is "average temp" downfall - not sure. Any more information anyone has on this, feel free to chime in! Thanks for any and all input!