CompactibleBlock

So I'm trying to make a multiblock fluid storage, but there aren't many sources to get help from. I'm planning for it to be 4x4, and sort of have connected textures, like the reactors from big reactors are. How would I do this?

No problem!

Check in your file explorer / finder settings. Is the 'show hidden files' on? Here's what it should look like.

So while searching through my mod, I've found some code-style issues and some problematic issues, and I don't want my mod to include unnecessary or old code. Is there any tutorial that contains the least issues or up-to-date code? Thanks.

I'll try to implement this into my code, and thanks for the response. This really helped me understand what they are.

So I was trying to create a custom furnace in 1.12.2, but whenever I tried to open the furnace, the game would crash. And then I tried to find out why, and apparently the code is outdated, and instead of using IInventory, I should use capabilities but I don't really know what it is and how to use it.