DaemonUmbra

Try this:

Sounds good so far

What are you talking about "in your minecraft folder" all you do is download the installer and run it, you should not be manually doing anything with the files.

You don't need to put Forge anywhere. Just run the installer, make a new Profile/Installation, select Forge, and play.

Not really, it just means you're less likely to know the issue or how to fix it if you've never managed mods manually.

Exactly how are you supposed to get tools if you can't punch trees? Please explain.

Check the 1.12.2 folder in your mods folder. This error comes from OTG putting a component of itself in that folder, which then crashes when you remove the rest of OTG.

The filenames of one or more of your mods suggests you got them from a repost site. Please read up on the StopModReposts project (link in my signature) for info on why this is a bad thing. Whatever the heck mw is, it's got a bad mod ID and is broken.

You're running the command wrong. Most likely forgetting the -jar argument before the forge jar name.

Please provide your debug.log as described in the EAQ

Threads merged. Don't do that again. Please provide your debug.log as described in the EAQ

Please provide a screenshot of this error message

At this time there is only one version of Optifine that is compatible and installable alongside Forge, and it's a preview version.

I would recommend backing up the mods, config, and saves folders from that, deleting everything else and renaming the folder, then putting mods, config, and saves back in. Game Directory doesn't need everything from the .minecraft folder.

Because the best case for checking server tickrate would be to make your mod check the tickrate on the server side and send that info to your mod on the client side. I don't understand this fascination with manipulating vanilla packets when having a server component of your mod is far safer and more reliable.

It's crashing because Forge 28.0.45 had breaking change in it that your version of Voxelmap is not updated for. Again on the concept of copying to your D drive, if you can put up with the file repository (versions and assets) being put on C, you can change the Game Directory of each Profile/Installation (where mods, logs, configs, and saves go) to be on D

Best thing would be to not mess with it at all, may I ask why you need to interact with Vanilla packets?

You mean besides allocating more?

You do know that unless you use command line options with the launcher it will have re-generated everything on C, right?

You are missing or have the wrong versions of mods that other mods require. Your debug.log will have more info.

Did anything else change between working and not, maybe a dimension change or adding a mod?

Does your brother own a copy of Minecraft?

Why is the server running in Offline mode?

What version?

Please read the Logs section of my signature below and provide the appropriate log in the appropriate manner.