Why does Forge 1.12.2 keep crashing?

I play Minecraft on a laptop (so now not so heavy hardware) and want to play with mods. But whenever I start Forge 1.12.2 it crashes immediately after 1 second and the error code is "0". I once heard that this actually means that the process was carried out successfully.

Can someone help me?

PS: Please do not answer such as "buy better hardware" or "install more RAM".

First try without starting mods. If possible, a mod blocks the start. If it doesn't work without mods, it's up to Forge. Either reinstall or use Fabric!

I've already tried it without mods. Always the same.

I downloaded Forge from the official website, but as an exe for Windows and not with Java. But it always worked that way in the past

If it doesn't work without Forge, it's because of Java. You need Java 8.

if it doesn't work without mods, then it's up to Forge: Reinstall Forge.

if it works without mods, but not with: take one out every time and see if it works. A mod doesn't work then. (maybe see if there are other compatible versions)

I have JRE 8

You could reinstall Forge

I will

OK, exactly the same, it crashes immediately😞

Try as .json, otherwise try Fabric.

It is strange. But does it work without Forge?

Yes

Then maybe try a different version of Forge as a test? Or download the jar file and give it a try?