01
Visual Version Changer Overview
On standard Pterodactyl panels, switching your Minecraft server software or updating to a new minor release requires manually downloading executable JARs, uploading them via SFTP, and modifying startup arguments.
Azion Cloud features the Version & Software Changer extension directly integrated into your server sidebar. It connects directly to official upstream software APIs (PaperMC, Purpur, Fabric Meta, NeoForged, CurseForge), downloads verified server binaries, and configures startup variables automatically.
| Supported Software | Target Use Case | Plugin / Mod Compatibility | Recommended Java |
|---|---|---|---|
| PaperMC | High-performance survival multiplayer (SMP) | Spigot, Paper, Bukkit plugins | Java 21 (1.20.5+) / Java 17 (1.18–1.20.4) |
| Purpur | Extreme performance with custom gameplay tweaks | Spigot, Paper, Purpur plugins | Java 21 / Java 17 |
| Fabric | Lightweight technical mods & high-FPS modding | Fabric mods (Fabric Loader + Fabric API) | Java 21 / Java 17 |
| Forge / NeoForge | Heavy modpacks & complex technical mods | Forge & NeoForge mod ecosystems | Java 21 / Java 17 |
| Vanilla Minecraft | Pure unmodified Mojang server experience | Datapacks only (No plugins or mods) | Java 21 / Java 17 |
02
How to Switch Server Software in 1 Click
- Take a Server Backup (Essential): Always create a snapshot before changing software. Go to Backups → click Create Backup.
- Stop the Minecraft Server:
Navigate to Console and click the red Stop button. Ensure the console outputs
Container server marked as offline. - Open Version Changer: In the left navigation sidebar, click Version Changer.
- Select Software & Build:
- Click the tab for your desired software (e.g. Paper, Purpur, or Fabric).
- Use the dropdown menu to choose your target Minecraft release (e.g.
1.21.1,1.20.4). - Select the specific upstream build (the extension highlights the latest recommended stable build by default).
- Choose File Preservation Options:
The installer presents a safe toggle:
- Keep Existing Files (Recommended): Replaces only the executable server JAR while preserving your worlds, plugins, and configurations.
- Clean Reinstall: Wipes old files if you are switching from modded to vanilla.
- Click Install Build:
The extension fetches the binary, sets the executable permissions, and updates your Pterodactyl startup variable (
SERVER_JARFILE). - Verify Java Version & Start: Check Startup Settings to ensure the Java Docker image matches your version (Java 21 for 1.20.5+), then click Start in the console.
World Downgrade Warning
Minecraft worlds cannot be safely downgraded to older versions (e.g. loading a 1.21 world on a 1.20 server will cause chunk corruption and missing block data). Only upgrade worlds forward, or restore an older backup before switching to a lower version.
03
Java Version Compatibility Matrix
Running an incompatible Java version is the #1 cause of UnsupportedClassVersionError crashes. Verify your startup settings against this official matrix:
| Minecraft Version Range | Required Java Runtime | Pterodactyl Docker Image Tag |
|---|---|---|
| 1.20.5 – 1.21.x+ | Java 21 | ghcr.io/pterodactyl/yolks:java_21 |
| 1.18 – 1.20.4 | Java 17 | ghcr.io/pterodactyl/yolks:java_17 |
| 1.17.x | Java 16 | ghcr.io/pterodactyl/yolks:java_16 |
| 1.12.2 – 1.16.5 | Java 11 or Java 8 | ghcr.io/pterodactyl/yolks:java_11 |
| 1.7.10 – 1.8.9 (Legacy Mods) | Java 8 | ghcr.io/pterodactyl/yolks:java_8 |