InvSee++ /invsee Command Not Working On Paper 1.21.9

Hey guys! Having trouble with the /invsee command in InvSee++ on your Paper 1.21.9 server? You're not alone! This article dives into a persistent issue where the /invsee command, and even /endersee, stubbornly refuses to function despite recent remapping updates. Let's break down the problem, understand the error messages, and explore potential solutions.

Understanding the Issue

The core problem is that after updating to Paper 1.21.9-57 and using InvSee++ plugin v3.30.10, the /invsee command, which should allow admins to view player inventories, simply doesn't work. This is a critical feature for server moderation and support. The issue extends to the /endersee command as well, which is used for viewing ender chest contents.

The user, Appletree2004, reported this problem while also running the Essentials and Multiverse-Inventories plugins. It's important to note that plugin conflicts can sometimes be the culprit, but the error log points towards a deeper issue within the InvSee++ plugin itself.

The Error Message Breakdown

The error message is quite descriptive, giving us a solid starting point for troubleshooting. Here's the relevant snippet:

[11:51:12 ERROR]: [InvSee++] Error while trying to create main-inventory spectator inventory
java.lang.IllegalAccessError: class com.janboerman.invsee.spigot.impl_1_21_9_R6.InvseeImpl tried to access private field net.minecraft.server.level.ServerPlayer.server (com.janboerman.invsee.spigot.impl_1_21_9_R6.InvseeImpl is in unnamed module of loader 'InvSee++.jar' @3c646e06; net.minecraft.server.level.ServerPlayer is in unnamed module of loader java.net.URLClassLoader @621be5d1)

Let's dissect this error:

• IllegalAccessError: This is a Java-specific error indicating that the code is trying to access a part of the code (a field, method, or class) that it doesn't have permission to access.
• com.janboerman.invsee.spigot.impl_1_21_9_R6.InvseeImpl: This is the class within the InvSee++ plugin that's causing the problem. It's specific to the 1.21.9 version of the game.
• net.minecraft.server.level.ServerPlayer.server: This is the private field that the InvSee++ plugin is trying to access within the Minecraft server code. The error indicates that InvseeImpl is attempting to access a private field of the ServerPlayer class, named server. Private fields, as the name suggests, are meant to be accessed only within the class they are defined in. This is a core principle of object-oriented programming called encapsulation.

In simpler terms, the InvSee++ plugin is trying to peek inside something it's not supposed to, and Java is preventing it. This usually happens when internal Minecraft code changes between versions, and the plugin hasn't been updated to reflect those changes.

Why is This Happening?

Minecraft server implementations like Paper often have internal code changes between versions. These changes, while not always visible to the end-user, can break plugins that rely on accessing specific internal fields or methods. In this case, the InvSee++ plugin is trying to access a private field (ServerPlayer.server) which may have been renamed, moved, or made inaccessible in Paper 1.21.9.

Even though "the remappings code merged in paper", as the user mentioned, this doesn't automatically guarantee that all plugins will work flawlessly. Remappings help bridge the gap, but plugins still need to be updated to be fully compatible with the new mappings and internal code structure.

Potential Solutions and Troubleshooting Steps

Alright, so what can you do to get the /invsee command working again? Here’s a breakdown of steps you can take:

1. Check for Plugin Updates

This is the first and most crucial step. Head over to the InvSee++ plugin page on SpigotMC, Bukkit, or wherever you downloaded it from, and see if there's a newer version available. The plugin author, Jannyboy11, may have already released an update to address compatibility issues with Paper 1.21.9.

2. Verify Plugin Dependencies

Some plugins rely on other plugins to function correctly. Check the InvSee++ plugin description to see if it has any dependencies. Make sure you have all the required dependencies installed and updated.

3. Rule Out Plugin Conflicts

Since you're using Essentials and Multiverse-Inventories, there's a chance one of them is interfering with InvSee++. Try temporarily disabling these plugins (one at a time) to see if the /invsee command starts working. If it does, you've identified a conflict.

If you find a conflict, you might need to adjust the configurations of the conflicting plugins or look for alternative plugins that offer similar functionality without causing issues. Reporting the conflict to the developers of both plugins can also help them resolve the problem in future updates.

4. Paper Version Compatibility

Double-check that the InvSee++ version you're using is specifically designed for Paper 1.21.9. Some plugins might have separate versions for different Minecraft server implementations or versions. Using the wrong version can lead to errors like the one you're experiencing.

5. Investigate Alternative Plugins

If all else fails, consider exploring alternative inventory viewing plugins. While InvSee++ is a popular choice, there might be other plugins that offer similar functionality and are compatible with Paper 1.21.9. Look for plugins with positive reviews and recent updates.

6. Consult the Plugin Author/Community

If you've exhausted all other options, reach out to the InvSee++ plugin author, Jannyboy11, or the plugin's community forum. They might be aware of the issue and have specific solutions or workarounds. Provide them with the error message and details about your server setup (Paper version, plugin versions, etc.) to help them diagnose the problem.

7. Downgrade Plugin Version (Use with Caution)

As a last resort, you could try downgrading to an older version of InvSee++. However, this is not recommended unless you're sure the older version is compatible with Paper 1.21.9 and doesn't introduce other issues. Older versions might lack important bug fixes or security updates.

8. Analyze the Stack Trace

The provided error message includes a stack trace, which is a detailed list of the sequence of method calls that led to the error. While it might look intimidating, the stack trace can provide valuable clues for developers. Here's how to approach it:

• Start from the top: The topmost lines of the stack trace indicate where the error originated within the InvSee++ plugin.
• Look for familiar class names: Identify the classes and methods within the InvSee++ plugin that are involved in the error. This can help pinpoint the specific functionality that's failing.
• Trace the call sequence: Follow the stack trace downwards to understand the sequence of method calls that led to the error. This can reveal the root cause of the problem.

For example, in the provided stack trace, we can see that the error occurs in com.janboerman.invsee.spigot.impl_1_21_9_R6.InvseeImpl.callInventoryOpenEvent. This suggests that the issue might be related to how the plugin is handling inventory open events.

Awaiting a Plugin Update

Ultimately, the most reliable solution is often waiting for the plugin author to release an updated version of InvSee++ that specifically addresses compatibility issues with Paper 1.21.9. Plugin developers often rely on feedback from users like you to identify and fix bugs. Reporting the issue to the plugin author is a valuable contribution to the community.

Conclusion

Dealing with plugin compatibility issues can be a real headache, but by systematically troubleshooting and understanding the error messages, you can often find a solution. Keep an eye out for updates to InvSee++, and don't hesitate to reach out to the plugin author or community for help. Happy server managing, and hopefully, you'll be peeking into player inventories in no time!

For more information about Minecraft server administration and plugin troubleshooting, check out the PaperMC documentation. It's a great resource for server owners!