Luis_ST

Due the log i would guess you are not running a server. The this depends on your Launcher. I only know the solution for the vanilla Launcher (include CurseForge): Go into the installations tab, edit the profile you are using. Open the more options and edit the JVM arguments and modify the -Xmx argument. The default value is 2G which are 2 Gigabyte, you can try to use 4G or 6G (you should choose a value based on the installed memory). If you start a server against my assumption, you can add/modify the -Xmx argument in the user_jvm_args file.

Could you please describe where the front actually is? since there are several interpretations of front. Show the code you are using to summon the Entities.

Inside the Event you can set the burn time of an Item which is used by the furnace To be simple, Events are called at some point x in the vanilla code and let you modify, change or register some stuff. The event concept is actually quite simple since all Event work the same, you only need to understand how to use them.

Are you sure the server and the client using the same Mods? Please post a screenshot of server and clients mods folder and the debug.log from the logs folder.

This is nothing which prevents the server from starting, you can ignore it. If the server does not start please post full debug.log or if this above is the full debug.log the command line output.

The game is running out of Memory (RAM). You need to give the game more Memory.

Please post debug.log from the logs folder.

Please post debug.log from server and client. Note on CurseForge you need to enable the debug.log in the settings.

This is not the debug.log from the logs folder. For the next time please create your own thread.

Create your own thread and post debug.log from the logs folder.

Problem with Valhelsia Core. Make sure you are using the latest version. If the Mod is already up to date, talk to the Mod author.

You can use a paste website like https://pastebin.com/ or https://gist.github.com/.

Unsupported version.

Please post debug.log from the logs folder.

If you had issues with adfoc.us you can use the direct download. You find it if you show all versions and then click in the i near the installer.

Please post debug.log from the logs folder.

Yes, would the next step.

Make sure you are using the latest version of Gobber 2. If the Mod is already up to date, talk to the Mod author.

Yes

I'll guess you mean the size of the ExtraStorageInventory, in your case the size is set in AttachCapabilities where you create ExtraStorageInventory, and in ClickBlock where you send the size to the client. If you change these values and handle the new Slot size in your ExtraStorageMenu you can expands the ExtraStorage. Note if you change the value you need to create a new World. Finally i found your issue, as D7 already told you can not use ITEM_HANDLER_CAPABILITY but this include IItemHandler. Due you use IItemHandler for your Capability it always return the already attached IItemHandler (the player inventory). The steps to solve this problem are easy: Create a new interface which extends IItemHandler Implement this interface in your ExtraStorageInventory Use this interface for your Capability and the LazyOptional

Is the code in your Git repo up to date? How did you open the Backpack? Did you tried a new World?

Remove Not Enough Animations from the server it's a badly coded client side Mod.

Please post a screenshot, so i can try to reproduce this.

You installed OptiFine on the server. Remove it.