CurseForge · Minecraft mod
rctapi fix
a fix for rctapi
Quick answer
Which rctapi fix release should I use?
rctapi fix rctapi-fabric-1.21.1-0.15.0-beta-academyfix.jar targets 1.21.1 with Fabric. The project page does not say whether this file belongs on the client, dedicated server, or both. No extra mods listed for this file.
Where it goes
Is rctapi fix required on the client, server, or both?
The project page does not say whether this file belongs on the client, dedicated server, or both.
The source does not explicitly classify this release as client-only or server-only.
What else does rctapi fix rctapi-fabric-1.21.1-0.15.0-beta-academyfix.jar need?
rctapi-fabric-1.21.1-0.15.0-beta-academyfix.jar. Change the file and its required mods may change too.
This file does not list any required mods. Do not add a library just because a different file uses it.
This file does not list any required or optional mods.
Before you install it
Add rctapi fix without breaking your instance.
Built for rctapi fix rctapi-fabric-1.21.1-0.15.0-beta-academyfix.jar. Pick another file and the loader, install side or required mods may change.
- 01
Stick to this file
Use rctapi-fabric-1.21.1-0.15.0-beta-academyfix.jar. It targets 1.21.1 with Fabric; another release may have different loader, side or dependency requirements.
- 02
Bring the mods it needs
This file does not list any required mods. Do not add a library just because a different file uses it.
- 03
Put it on the correct side
The project page does not say whether this file belongs on the client, dedicated server, or both.
- 04
Pick the file you checked
Use the “Get this file” button beside rctapi-fabric-1.21.1-0.15.0-beta-academyfix.jar. It opens that exact file at the source.
About this project
What does rctapi fix add?
RCTAPI Academy Fix
This is a compatibility patch for the Radical Cobblemon Trainers API (rctapi) mod, designed specifically for modpacks using Abes Hutt's Cobblemon fork (branch academy-1.7.1).
What does this mod do?
Abes Hutt's Cobblemon fork modified the signature of BattleRegistry.startBattle() by adding an optional Function2 callback parameter. This change breaks compatibility with any mod that calls this method using the original signature, causing a server crash whenever a battle is initiated.
This fix patches BattleManager.startBattle() inside rctapi to call BattleRegistry.startBattle$default() instead, passing the appropriate Kotlin default parameter mask. This makes rctapi fully compatible with the modified Cobblemon fork without altering any gameplay behavior.
Who needs this?
Any modpack that includes:
- Abes Hutt's Cobblemon fork (academy-1.7.1)
- rctapi 0.15.0-beta
- Any mod that depends on rctapi, such as Cobblemon Battle Tower or Rad Gyms
What is affected?
- Cobblemon Battle Tower battles will no longer crash the server
- Rad Gyms battles will no longer crash the server
- All other rctapi functionality remains unchanged
This mod is a fork of rctapi 0.15.0-beta by hd42, modified under the GNU LGPL-3.0 license.
Project description from CurseForge.
Pick your setup
rctapi fix by Minecraft version and loader
Choose the version and loader you play, then open the matching release.
Check the dependencies, then try the file in a copied instance before changing a world you care about.
Recent files
rctapi fix versions and loaders
rctapi-fabric-1.21.1-0.15.0-beta-academyfix.jar
19 Apr 2026
Looking for an older file? The official CurseForge project page is in Resources.