Crash Report
Full Log

I have installed all 4 files for Mekanism: Mekanism-116.1-10.0.0.423, Generators-1.16.1-10.0.0.423, Tools-116.1-10.0.0.423, Addons-116.1-10.0.0.423.
Game crashes upon startup, giving me this error: Error: java.lang.NullPointerException: Registry Object not present: mekanismadditions:black_plastic

The crash report shows us due to this forge bug that causes the real crash to be hidden. In your latest log there is this message (and the start of the actual crash). It seems that better bedrock requires mixin bootstrap.

[12:58:28] [modloading-worker-3/ERROR]: Failed to create mod instance. ModID: betterbedrockgenerator, class be.nevoka.betterbedrockgenerator.BetterBedrockGenerator
java.lang.IllegalStateException: This is an expected crash because MixinBootstrap isn't (properly) installed. 
You can download it from: https://github.com/LXGaming/MixinBootstrap/releases 
Copy the jar into your mods folder.
	at be.nevoka.betterbedrockgenerator.BetterBedrockGenerator.<init>(BetterBedrockGenerator.java:20) ~[?:0.0.7]

I installed mixin bootstrap but there's still a crash with the same error message.
Crash log
Full log
Btw, for future reference, where do I find the layout to post in the proper format? I looked around and I couldn't really find one.

Nevermind I have found where to find the layout. somehow I was given a blank entry when creating a new issue

No idea the latest log still claims that you don't have mixin bootstrap installed or that it is not properly installed.

That's correct, the download failed. the game doesn't crash anymore, thanks for the assistance