☰

How MCDoctor.ai Works

MCDoctor uses advanced AI diagnostics to read, interpret, and explain Minecraft server errors, crashes, and plugin conflicts with precision. Instead of scrolling through thousands of lines in latest.log, MCDoctor extracts the root cause automatically and generates a clear, structured report you can understand instantly.

Smart Log Processing

MCDoctor automatically cleans your log, removes unnecessary noise, extracts errors, warnings, crash signatures, plugin issues, and version conflicts, preparing it for deep AI analysis.

AI Deep Understanding

Using a specialized Minecraft-trained AI pipeline, MCDoctor reads the log as if an expert moderator or server engineer was looking at it, detecting patterns, mod/plugin failures, misconfigurations, missing dependencies, and more.

Clear Human-Readable Explanations

You receive a clean HTML report: Cause → Fixes → Notes. No jargon. No guesswork. MCDoctor explains every issue in simple steps you can follow.

Built for Every Minecraft Server

Whether you're running Paper, Purpur, Fabric, Forge, NeoForge, Spigot, or Modpacks, MCDoctor adapts the analysis to your platform and resolves issues specific to each ecosystem.

Now let’s explore how the upload and analysis sequence actually happens below.

What Happens Behind the Scenes?

When you upload a log, MCDoctor runs a fast, multi-step diagnostic pipeline. Here’s a clear breakdown of how your log is processed.

1/ Log Reading & Cleaning

MCDoctor loads your latest.log, removes noise, restructures the file and prepares it for analysis.

2/ Platform Detection

The system identifies whether you’re running Paper, Purpur, Spigot, Fabric, Forge or NeoForge, adapting the analysis to your server type.

3/ Error & Plugin Analysis

MCDoctor extracts crashes, warnings, plugin errors, missing dependencies and version conflicts to isolate the real issue.

4/ Root Cause Understanding

Using Minecraft-trained AI, MCDoctor compares your errors with known patterns to identify the true cause.

5/ Clear Human-Readable Report

You receive a structured HTML report with: Cause, Fixes and Notes. Simple, clear, and fast.

2 analysis mode

Choose how deep you want MCDoctor to investigate your logs

Fast Diagnostic

Standard

Perfect for Vanilla, Paper/Spigot setups, and lightweight configurations.

  • Vanilla & Spigot/Paper server crashes
  • Common Plugin conflicts & exceptions
  • Java version mismatches & basic Out-of-Memory issues
  • Network connection & login routine errors
  • Immediate turnaround for standard infrastructure failures

⏱️ Around 10 seconds

Deep Analysis

Advanced

The expert AI engine engineered for heavy modded setups and deep infrastructure debugging.

  • Includes everything in the Standard tier
  • Heavy Modpacks (Forge, Fabric, NeoForge ecosystems)
  • Complex Mixin conflicts & Coremod loading failures
  • Deep-dive profiling for performance bottlenecks & TPS drops
  • Corrupt worldgen data & unstable block entity isolation
  • Context-aware log filtering (isolates true root causes from normal warning noise)

⏱️ Around 30 seconds

Tell MCDoctor What's Wrong

Selecting your server's symptoms before uploading guides the AI toward the right diagnostic lens, so it focuses on what actually matters in your log, not everything at once.

Standard

Generic scan

Reads the entire log blindly, no context, no focus. You get a broad overview but the AI may miss the root cause buried in logs.

  • Full log sweep
  • No problem context
  • Generic fixes
VS
Advanced + Symptoms

Targeted diagnosis

You tell MCDoctor what's wrong, the AI locks onto the right log sections and delivers sharper, faster, more actionable results.

  • Focused log filtering
  • Symptom-aware AI
  • Precise fixes
What is your server experiencing? Click to highlight, purely illustrative here
Targeted root cause

The AI skips irrelevant noise and zeroes in on the log sections matching your symptom type.

Faster diagnosis

Less ambiguity means the model resolves the cause in fewer reasoning steps, and produces a sharper report.

Smarter fixes

Solutions are scoped to your actual problem, crash fixes when you're crashing, performance fixes when you're lagging.

Example of AI Result

This is a realistic MCDoctor Advance Report, using our advanced rendering engine.

Cause

Your server is running several plugins that are not compatible with your current Paper/Minecraft version (1.21.5), or are missing required dependencies. Because of this, some plugins fail to start correctly and then throw a lot of “NullPointerException” errors (which basically means “this thing the plugin expected to exist is actually empty / not loaded”).

  • Multiverse suite (Core, Inventories, Portals, NetherPortals)
    • Multiverse-Core fails with “VerifyError” and config loading errors. That means the version you’re using is not built for your server version, or its files are broken.
    • Because Multiverse-Core never initializes, the other Multiverse plugins (Inventories, Portals, NetherPortals) also fail and throw errors like:
      • “MultiverseCore has not been initialized!”
      • “Cannot invoke ... InventoriesDupingPatch.disable() because this.dupingPatch is null”
  • PhoenixDuels
    • PhoenixDuels crashes on startup with “ExceptionInInitializerError”.
    • After that, its internal helpers are never set up, so you see:
      • “ServerVersion.CURRENT_VERSION is null”
      • “Utilities.ASYNC_SERVICE is null”
      These are just the plugin trying to use things that never got initialized because it failed to start.
  • Database / stats plugin (ResultSet is null)
    • Repeated errors like “Cannot invoke ResultSet.next() because resultSet is null” mean a plugin that talks to a database (MySQL/SQLite) is failing to get data.
    • Most likely:
      • Database connection is not set up correctly (wrong host, user, password, or database name), or
      • The plugin is not handling failed queries properly.
  • Other plugin issues
    • BanAnnouncer cannot load because it is missing the required plugin “Spicord”.
    • Essentials says you are on an unsupported server version, so that version of Essentials is not meant for 1.21.5.
    • ItemsAdder is missing a bunch of images for “betterranks” (admin.png, mod.png, etc.), so those custom rank icons won’t show up.
    • Some plugins log “VerifyError: Bad type on operand stack” – this is another strong sign they are compiled for a different Minecraft/Java version than what you are running.

Fixes

  • Update or remove incompatible plugins
    • Check each of these plugins and make sure you are using a version that explicitly supports Paper / Minecraft 1.21.5:
      • Multiverse-Core, Multiverse-Inventories, Multiverse-Portals, Multiverse-NetherPortals
      • PhoenixDuels
      • Essentials (or switch to EssentialsX with a version that supports 1.21.5)
    • If there is no 1.21.5-compatible version of a plugin, you have two options:
      • Temporarily remove that plugin from the plugins folder, or
      • Downgrade your server to a Minecraft version that the plugin officially supports.
  • Fix Multiverse specifically
    • Download the latest Multiverse plugins that support your server version from their official pages.
    • Delete or move aside old Multiverse config files if they are very old or corrupted:
      • Stop the server.
      • Backup the plugins/Multiverse-* folders.
      • Optionally remove the configs (so they regenerate) if you suspect they are broken.
      • Start the server and let new configs generate, then reconfigure worlds/portals as needed.
  • Fix PhoenixDuels errors
    • Get a PhoenixDuels version that supports your exact Minecraft/Paper version.
    • If none exists yet:
      • Remove PhoenixDuels from the plugins folder, or
      • Use a different duels plugin that is updated for 1.21.5.
  • Fix database / ResultSet null errors
    • Identify which plugin is logging “ResultSet.next() because resultSet is null” (look just above those lines in the full log for the plugin name).
    • Then:
      • Open that plugin’s config file (usually in plugins/PluginName/config.yml).
      • Check the database settings:
        • Host (IP / domain)
        • Port
        • Database name
        • Username and password
      • Make sure the database actually exists and the user has permission to access it.
      • Restart the server after fixing the config.
  • Install missing dependencies
    • For BanAnnouncer:
      • Download and install Spicord (the dependency it complains about).
      • Make sure you use versions of BanAnnouncer and Spicord that support 1.21.5.
  • Fix ItemsAdder missing images
    • Go to your ItemsAdder pack folder (usually plugins/ItemsAdder/data/resource_pack/assets/betterranks/textures/).
    • Add or restore the missing PNG files:
      • admin.png, mod.png, helper.png, player.png, builder.png, youtube.png, patreon.png, patreon2.png, java.png, skript.png, developer.png, dev.png, vip.png, vipplus.png
    • Run ItemsAdder’s command to rebuild the resource pack (check its documentation, usually something like /iazip or similar).
  • General cleanup steps
    • After making changes:
      • Stop the server completely.
      • Remove any obviously broken or outdated jars from plugins.
      • Start the server and watch the console for new errors.
    • Fix errors one plugin at a time so you can clearly see what changed.

Notes

  • Most of these errors are not caused by your world or your server hardware, but by plugin versions not matching your Minecraft/Paper version or missing dependencies.
  • If you are unsure which plugin is causing a specific error, you can temporarily:
    • Move all plugins out of the plugins folder,
    • Add them back one by one, restarting each time,
    • And see when the error returns. That tells you exactly which plugin is responsible.
  • Always back up your world and plugin folders before removing or changing plugins, especially big ones like Multiverse or ItemsAdder.