DaemonUmbra

Please provide a screenshot of your mods folder.

Please provide the file it mentions.

1.7.10 is no longer supported on this forum due to its age. Please update to a modern version of Minecraft to receive support.

"I have read this entire thread, seen your request, and rather than supply the file you asked for I'd rather just say I have the same problem, please fix it" Thanks...

Update to the latest version of Java 8. https://adoptopenjdk.net

See in the window where it says "Loading Json" right before it breaks? It tells you what file it broke on and I've yet to see the file that breaks the installer.

Can I get a screenshot of the message?

What are you running your server on? This crash is the result of the server running too slow to be playable so it gives up.

Please provide the file it says is corrupted.

In 1.12.2 you have to run the "setupDecompWorkspace" Gradle task, then refresh Gradle and Forge will show up as a dependency.

Where are you getting your mods?

Optifine does not have a version compatible with Forge yet and this is on the Optifine Dev to figure out.

That's a Necro and a Hijack, well done. Locking...

Holy infinite loop, batman. Stacktrace mentions Malisis Core and Secret Rooms Mod, not sure if this is an interaction issue or an issue with just one of them.

Have either of you opened my signature? Are either of you on mobile?

Forge installs itself as an available Minecraft version, make a new Profile/Installation and select your desired version of Forge.

What launcher are you using? Please provide screenshots of your launcher with the versions list open.

Please do not hijack threads, if you have an issue please make your own.

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

No, you must use the installer. Try updating to the latest Java 8.

Sorry, the link I posted is not relevant in this instance, I misread. Try deleting the file it specified, then re-running the Minecraft launcher to re-download it before running the Forge installer again

That looks like a game log, I was asking about the installer log.

You shouldn't need to modify anything manually, doing so usually complicates things. I believe it's only failing at a last, unnecessary hurdle though, so the server should work even after failing like this. https://GitHub.com/MinecraftForge/InstallerTools/pull/1

Forge will target what Minecraft targets, and right now that means 8

Check out https://adoptopenjdk.net