Search your exact error first
Type a keyword from your error message or describe the problem in the search box below — it'll filter to the relevant fixes instantly. If nothing matches, the Cobblemon Discord is the best place for specific issues.
Quick Fixes — Try These First
Before diving into specific errors, these five steps resolve the majority of Cobblemon issues and take under 2 minutes to try.
1
Check your Cobblemon version matches your Minecraft version. Cobblemon 1.7.1 requires Minecraft 1.21.1. Mismatches cause most crashes.
2
Allocate at least 4GB RAM to your Minecraft instance. Most problems are memory-related.
3
Make sure you have Java 21. Minecraft 1.21.1 requires Java 21 — older Java versions cause instant crashes.
4
Remove all other mods and test Cobblemon alone. If it works alone, add mods back one at a time to find the conflict.
5
Delete the config folder in your Cobblemon instance and let it regenerate. Corrupted config files cause odd behaviour.
Error Database
Minecraft crashes immediately on launch
"The game crashed whilst initialising game" or black screen then crash
Install
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Most likely causeWrong Java version, insufficient RAM, or a mod conflict. Cobblemon 1.7.1 requires Java 21 and Minecraft 1.21.1.
1
Open your launcher settings and confirm you're using Java 21. In Modrinth App: Settings → Java → select Java 21.2
Increase RAM allocation to at least 4GB (6GB recommended). In Modrinth: Instance settings → Memory.3
Check your crash log — find it in .minecraft/logs/crash-reports/. The last line of the crash report names the problem mod.4
If a mod is named, remove it and test. If there's no mod named, reinstall the Cobblemon modpack fresh from Modrinth.Paste your crash report into the Cobblemon Discord #support channel for specific help.
Cobblemon doesn't appear in the Mods list
Game launches but no Pokémon spawn and Cobblemon isn't in the mod list
Install
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Most likely causeCobblemon.jar is in the wrong folder, using the wrong mod loader build, or the mod loader itself isn't installed.
1
Confirm you have Fabric Loader installed (or NeoForge if using the NeoForge version). Cobblemon won't load without a mod loader.2
Check the mods folder path: .minecraft/mods/ for standard installs, or the instance's mods folder in Modrinth/CurseForge.3
Make sure you downloaded the correct build — the Fabric .jar won't work with NeoForge and vice versa.4
The simplest fix: use the official Cobblemon modpack on Modrinth or CurseForge — it installs everything automatically in the right place.Out of Memory crash during gameplay
"java.lang.OutOfMemoryError: Java heap space"
Install
Performance
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Most likely causeNot enough RAM allocated to Minecraft. Cobblemon with mods needs more memory than vanilla.
1
Increase RAM to 6GB minimum for modded Cobblemon, 8GB if using a modpack with many addons.2
Don't allocate more than 75% of your total system RAM. If your PC has 8GB total, cap Minecraft at 6GB maximum.3
Add the Lithium and Sodium performance mods alongside Cobblemon — they significantly reduce memory usage.Mod loader version mismatch error
"This mod requires Fabric Loader 0.x.x or higher" or similar
Install
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Most likely causeYour Fabric or NeoForge version is outdated relative to what Cobblemon 1.7.1 requires.
1
In Modrinth App, open your instance → Edit → select the latest Fabric Loader version and save.2
For CurseForge: profile settings → change Fabric version to the latest stable release.3
Simplest fix: delete the instance and reinstall the Cobblemon modpack fresh — it comes with the correct loader version pre-configured.No Pokémon spawning anywhere
Walked around for 10+ minutes, no Pokémon appear in any biome
Spawns
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Most likely causeCobblemon isn't loaded, spawn distance is too low, or you're in a newly generated world that hasn't populated yet.
1
Wait 2-3 minutes after world load — spawning takes time to initialise, especially in new worlds.2
Check cobblemon.yml config — find spawnDistance and make sure it isn't set to 0.3
Use /spawning debug (requires OP) to see what Cobblemon thinks should spawn at your location.4
Try a different biome — some biomes have very low or no spawn rates by default. Forest and plains have the highest density.5
Confirm in the Mods list that Cobblemon is actually loaded — if it's missing from the list the spawn system simply won't run.Specific Pokémon won't spawn
Looking for a specific Pokémon in the right biome but can't find it
Spawns
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Most likely causeWrong biome, wrong time of day, low spawn weight, or the Pokémon requires a specific biome variant you don't have.
1
Double-check the biome requirement in our spawn locations guide. Many Pokémon require specific sub-biomes, not just the broad type.2
Check the time of day requirement — many rare Pokémon are night-only or day-only.3
Rare Pokémon have very low spawn weights — you may need to explore for 20-30 minutes in the right spot before finding one.4
Install the Biome Expanded Spawns datapack — it dramatically improves spawn variety across all biomes.Too many Pokémon spawning — causing lag
FPS drops in areas with lots of Pokémon, mobs everywhere
Spawns
Performance
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Most likely causeSpawn rates too high in config, or too many spawn datapacks installed simultaneously.
1
In cobblemon.yml, reduce the pokemonPerChunk value. Default is 6 — try 3-4 for better performance.2
Check for conflicting spawn datapacks. If you have multiple spawn datapacks installed they can stack rates and produce too many Pokémon.3
Reduce your render distance — Cobblemon loads Pokémon within the render distance, so lower render = fewer entities.Battle screen is stuck or frozen
Battle UI loads but won't respond to clicks, or gets stuck on a white screen
Battle
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Most likely causeBattle engine desync, usually caused by a mod conflict or a resource-limited system struggling to process the battle state.
1
Try /pokeflee command to force-escape the battle.2
If stuck in multiplayer, have an admin run /forcecatch [your name] to end the battle state.3
Press Escape to close the UI, then relog. Your Pokémon's HP should return to pre-battle state.4
If it happens repeatedly, check for conflicting mods that modify the battle UI (custom HUD mods are common culprits).Moves dealing wrong damage or not working
Moves appear to deal no damage, wrong type effectiveness, or PP shows as empty
Battle
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Most likely causeStale move data from a previous version, or a Pokémon with incorrect moves from an old save file.
1
Run /pokeheal to reset PP and status — sometimes PP display bugs are purely visual and heal fixes it.2
For persistent damage bugs: move the affected Pokémon to the PC and retrieve it — this refreshes its data.3
If type effectiveness seems wrong, double-check the Pokémon's typing — some Cobblemon species have different typings to the mainline games.PC won't open or shows blank
Right-clicking the PC block does nothing, or PC opens but shows no Pokémon
Storage
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Most likely causePC block placed incorrectly, data not loaded yet, or a UI mod conflicting with Cobblemon's interface.
1
Try the /pc command instead of right-clicking the block — if this works the block itself is the problem.2
Break and replace the PC block. Sometimes the block entity data fails to initialise on placement.3
Relog — player data sometimes doesn't sync immediately on world load. A relog forces a fresh data fetch.4
Check for inventory/UI mods. Mods like InventoryTweaks can interfere with Cobblemon's PC interface.If Pokémon appear missing: run /testpcstore [username] (admin only) to check data integrity before panicking — they're almost always still there.
Pokémon appear to be missing from PC
Previously stored Pokémon no longer showing in PC boxes
Storage
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Most likely causeDisplay bug, data loading issue, or a world save that hasn't fully loaded player data yet. Actual data loss is rare.
1
Don't panic. Actual data loss is rare — most "missing Pokémon" reports turn out to be loading issues.2
Fully close Minecraft and relaunch. Don't just relog — fully close the launcher and restart it.3
Check all PC boxes including Box 1 — sometimes the PC opens on the wrong box and Pokémon appear missing when they're just on a different page.4
On servers: contact an admin and ask them to run /testpcstore [your name] to check data integrity.5
Check your world save's cobblemon/ folder — player data files should be present. If they're there, the data exists.If data is confirmed lost on a server, most well-run servers have backup restores they can run. Contact staff immediately.
Low FPS and stuttering with Cobblemon
Game runs poorly — under 30 FPS, freezes when Pokémon spawn, general lag
Performance
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Most likely causeInsufficient RAM, too many Pokémon entities loading at once, or missing performance optimisation mods.
1
Add Sodium (render optimisation), Lithium (game logic optimisation) and FerriteCore (memory reduction) to your mods folder.2
Reduce render distance to 8-10 chunks. Cobblemon spawns within render distance, so lower render = fewer entities.3
In cobblemon.yml, reduce pokemonPerChunk from the default to 3-4.4
Turn off fancy graphics options in Cobblemon settings — animated Pokémon models are resource-intensive.Can't connect to a Cobblemon server
"Connection refused", "outdated client", or just can't connect at all
Server
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Most likely causeWrong Minecraft/Cobblemon version, wrong server IP, or the server requires a specific modpack you don't have installed.
1
Check the server's Discord or website for the required Minecraft version. Most Cobblemon servers are on 1.21.1.2
"Outdated client" means your Minecraft version is wrong. Update to the version the server requires.3
Some servers (like Cobblemon.gg) require their own specific modpack. Check the server's site before trying to join.4
If the IP simply times out, check the server's Discord — it may be down for maintenance or the IP may have changed.Server-side lag — battles and spawns are delayed
Everything works but feels slow — battles take time to respond, Pokémon spawn late
Server
Performance
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Most likely causeServer TPS (ticks per second) is below 20, usually due to too many Pokémon entities or an underpowered server.
1
This is a server-side issue — report it to the server staff. Individual players can't fix TPS problems.2
If you run the server yourself: reduce pokemonPerChunk in cobblemon.yml and add Lithium to the server.3
Check how many players are online — high player counts with lots of Cobblemon activity will always stress a server.
Still stuck?
The official Cobblemon Discord has a #support channel staffed by experienced community members. Paste your crash log or describe your issue — most problems get solved within an hour.