JaariAtmc

Nah, its because Forge broke the old workflow in 1.13. There's no fix other than using the Twitch/Curse Launcher.

Oh yes, the usual fix is actually getting rid of MCleaks influence by going to their site and checking how to actually fully uninstall the crappy hack.

So, when you added Forge, did you put it in the bin or mods folder, and did you rename it or not?

It would help if you would state the full Forge version you've added. Not the error you get. The version you added yourself.

Have him upload his logs to pastebin and post those here.

Check if the Xbox minecraft app is the same as Minecraft Java Edition. This launcher ONLY works with Minecraft Java Edition. Windows 10 Edition is NOT the java edition.

Download Java 64bit. That's the OFFLINE installer. DO !!!!!!NOT!!!!!! USE THE ONLINE INSTALLER. End of PSA.

No, that's user error or an otherwise crappy pc. Like, no logs, no nothing.

Please don't necro a year old post, especially considering pixelmon is some 400 MB bloat mod.

Alright, bye hitler.

"What mods did you add? For which MC version? What Forge version did you add?"

Not being able to use more than 3.5 gigs means there's only 4 gigs in the laptop. Of which you can only effectively use 3 GB max. (1 GB for OS and other programs you might have open).

Provide a screenshot of your logged in launcher.

Tell them to buy minecraft.

Go to configs folder, go to forge.cfg, turn on removal of erroring tile entities. Restart server, check if removed.

Locate the worldsave of your world, and delete the Dimdoors folder. Your computer suddenly shut down, didn't it?

Which will absolutely not work, as this is an issue with a cracked launcher.

See what's using that RAM, if its not system, or something very important, close it, and allocate 6 GB for the 1.12.2 pack.

Yes. It has 8 GB. How much of it is already in use? "You have an income of 800 dollars. If you have to spend 400 dollars on your rent, why can't you spend 700 on entertainment?".

Why did you include a version of SImplyJetpacks that's for MC 1.6.4?

You cannot allocate 7 GB RAM if you don't have 7 GB available.

Actually install java 64bits.

Remove java version 9-14, install java 8.

Run this. https://www.intel.com/content/www/us/en/support/detect.html

And the reason this isn't an issue for any other launcher is because there are no other launchers with ACTIVE modpacks below MC 1.6.