Luis_ST

did you declared all dependencies you use in the mods.toml

you can take a look at the VineBlock

post debug log, you can use https://gist.github.com/ to upload the file

There was a problem with FPS Reducer. Make sure you are using the latest version. If the Mod is already up to date, report this bug to the Mod author.

post the link to the repo here

post debug log

you need a custom WalkGoal for your Entity, you can take a look at the vanilla NearestAttackableTargetGoal in your custom Goal you need to override canUse check there the conditions you want that your Entity can use the Goal

update Forge to the latest version

Problem with Pehkui. Make sure you use the latest version of the mod, if you already use the latest version report the bug to the mod author.

every resource file need to be all lower case, means Models, Blockstates, LootTables and Recipes

what did you mean by remove Effects from Item, also no not create Objects in a static fields, create them directly in the constructor

Problem with Config Swapper. Report this bug to the mod author since the mod does not use the Forge config system correctly

depends on the host you use, if you host the server on your server you can set the max player count in the server.properties file, if you use a online host service you need to add more player slots

copy the old world from the world folder into the new world folder of the new server

Problem with Bookshelf. Make sure you are using the latest version. If the Mod is already up to date, report this bug to the Mod author.

Could be a issue with CraftTweaker, Oh The Biomes You'll Go or Valhelsia Structures

you could open the Gui via NetworkHooks#openGui when your Block is right clicked you can take a look st the AbstractFurnaceBlock as an example, before you open the Gui you need to check if the structure is near by gor this you can check out the LocateCommand

this kind of crash normally happens if you have a issue in the Registration, make sure you use DeferredRegister for all vanilla Registries this include ConfiguredFeatures and PlacedFeatures

there is no error in the log you post, make sure it was the full log. If this was the full log post launcher log

there is no matching constructor in your Entity class, use your IDE to create the correct constructor

post debug log

post debug log from server and client

post debug log, also make sure you use a compatible version of Optifine

remove the ip and post debug log, the server should run fine without ip

Problem with WorldEdit, make sure you use the latest version of the mod. If you already use the latest version report this bug to the mod author.