If Verity JE crashes when you try to run it with NeoForge, the cause is usually simple: the loader and the mod build do not match, or GeckoLib is missing. Both problems are fixable in a few minutes, once you know which one you have. This page covers NeoForge crashes only.
First, a point that saves a lot of wasted time. Verity JE by VarmiteYT is a Java 1.20.1 mod made for Forge. A NeoForge build for 1.21.1 has been listed as deprecated in the mod’s own status, so it is not a safe starting point if you want a stable game. If you are running NeoForge and the game will not start, do not assume the mod itself is broken. Work through the checks below in order, and change only one thing at a time, so you can tell which fix actually worked.
First, find out why it crashed
Guessing wastes time. A crash report tells you, in plain terms, what the game was doing when it stopped. Before you reinstall anything, find and read that report.
On a normal Minecraft install, crash reports are saved in the crash-reports folder inside your .minecraft folder. Open the launcher, go to the installation you use for Verity, and open its game folder if you are not sure where it is. Inside .minecraft, open the folder called crash-reports, then open the newest file. Files are named by date and time, so the latest crash is usually at the top when the folder is sorted by date.
Near the top of the report, look for a short description of the crash and for the lines that name a mod or a missing class. You do not need to understand every line. Look for names you recognise, such as Verity, GeckoLib, Forge, or NeoForge, and for words such as ClassNotFoundException. That last one matters a lot: if the report mentions a GeckoLib class that could not be found, it means the game tried to load code that depends on GeckoLib, but GeckoLib was not there. That points straight to Fix 2 below.
Also check the first lines for the Minecraft version and the loader the game actually used. If those do not match the files in your mods folder, you have a version problem, not a problem with your world or your saves. Write down, or take a screenshot of, the key lines before you change anything. If you later need help, that report is the most useful thing you can share.
Fix 1: match the loader version
This is the most common NeoForge crash, and it is also the easiest to make by accident. A mod build made for one Minecraft version and one loader will not run cleanly on a different version or a different loader, even if the file names look similar.
For Verity JE, the safe combination is Minecraft 1.20.1 with a 1.20.1 Forge build. That means the loader you pick in the Minecraft launcher, the Verity file, and GeckoLib must all be for 1.20.1. In particular, never try to run a 1.20.1 Verity build on a 1.21.1 loader. The game version, the loader version, and the mod version must line up, or the game may close during loading before you ever reach the main menu.
To check this, open the launcher and look at the installation or profile you use for Verity. Confirm that it is set to the Forge profile for 1.20.1, not a NeoForge profile for a newer version and not a plain Minecraft profile with no loader at all. Then open your mods folder and check the file names. If you see a file for a different Minecraft version mixed in with your 1.20.1 files, remove it from that folder. Do not leave it there in the hope that the game will ignore it, because the loader will try to load it.
NeoForge and Forge are related, but they are not the same loader, and a build made for one cannot be assumed to work on the other. If you chose NeoForge because it sounded newer, that choice alone can be the cause of the crash. Switching back to the matching Forge setup for 1.20.1 is not a step backwards. It is the setup the mod was made for. For a general walkthrough of the Forge setup, see our Forge guide.
Fix 2: install or update GeckoLib
Verity JE needs GeckoLib. GeckoLib is a separate library mod that provides the animation code Verity uses. Without it, or with a version of it that does not match your game version, the game can crash while it is loading mods.
Open your mods folder and look for GeckoLib. If it is not there at all, that is your answer. If it is there, check that it is the Forge version for Minecraft 1.20.1. A GeckoLib file made for a different loader or a different Minecraft version can cause the same kind of crash as a missing file, so an old or mismatched copy is not good enough.
To fix it, put one correct GeckoLib file for Forge 1.20.1 into the same mods folder as Verity, then launch the game again. If you already had GeckoLib, replace it with a fresh copy for the correct version rather than adding a second copy beside it. Two versions of the same library in one folder can clash, and the game may load the wrong one first.
How do you know this was the problem? The crash report gives it away. A line that mentions a GeckoLib class that could not be found, such as a ClassNotFoundException naming GeckoLib, means the game expected GeckoLib and could not find it. If that line disappears after you add the correct GeckoLib file, and the game loads, you have found and fixed the crash.
Fix 3: check the Verity .jar itself
If the loader matches and GeckoLib is correct, the Verity file itself is the next suspect. A file can be damaged while downloading, saved in the wrong place, or copied twice, and any of those can stop the game from loading.
Open your mods folder and look for Verity. There should be exactly one Verity .jar file, and it should be the Java Edition file for 1.20.1. Remove any second copy, any file with a similar name that ends in a number such as (1), and any file that is clearly for another edition or version. A duplicate may look harmless, but the loader may try to load both copies and fail.
Also check that the file is in the mods folder for the profile you actually launch, not in Downloads and not in a different installation’s folder. A common mistake is to download the file, then launch a different profile, so the game never sees it or sees an old copy instead. If the file size looks very small, or the download was cut short, replace it with a fresh download and test again.
Then run a fresh profile test. Create a new launcher profile for Forge 1.20.1, put only Verity and GeckoLib in its mods folder, and launch it. If the game starts, the problem was in your old profile, such as another mod, a duplicate file, or a wrong setting. You can then add your other mods back one at a time until the crash returns, which will show you the clash. If the fresh profile still crashes with only Verity and GeckoLib, the problem is in the core setup, so return to Fix 1 and Fix 2 and check each version again.
If it loads but Verity never speaks
This is a different problem from a crash, and it needs a different check. If the game loads, Verity appears, but Verity never speaks, the game has not crashed. It is waiting for the voice setup to work.
Verity JE needs a free Groq API key to talk. Check that a key has been entered in the mod settings, that it was pasted in full with no extra spaces at the start or end, and that it is the key for the account you mean to use. A missing key, a half-pasted key, or a key from the wrong place will leave Verity silent even when everything else is set up correctly. Full step-by-step detail for this setup lives on our Java Edition guide, so use that guide for the full key walkthrough and keep this page for crash fixes.
When nothing works
If you have matched the versions, added the correct GeckoLib, and checked the Verity file, try a clean profile. Make a new Forge 1.20.1 profile, add only Verity and GeckoLib, and test it in a new world. Then test Verity alone, with no other mods. If that clean test works, add your other mods back one at a time to find the clash.
If even the clean, one-mod test crashes, re-read your crash report and check the version lines once more. When you ask for help, share that report and list your Minecraft version, your loader, and the files in your mods folder. That detail helps others spot a mismatch quickly. For wider problems beyond NeoForge crashes, see our general troubleshooting guide.
Conclusion
Most NeoForge crashes with Verity JE come down to a version mismatch or a missing GeckoLib file. Fix the match first, add the right GeckoLib, check for a duplicate or damaged .jar, and use a clean profile to prove where the problem lies. Once you play with friends, you may also find our guide on how to play Verity mod with friends useful.
Why does Verity JE crash on NeoForge?
Most often, the loader and mod versions do not match, or GeckoLib is missing. Verity JE is made for Forge 1.20.1, so a mismatched loader or a missing library can stop the game during loading.
Can I use a 1.20.1 Verity build on a 1.21.1 loader?
No. Use a 1.20.1 build on a 1.20.1 loader. Mixing versions is a common cause of crashes, even when the files look similar.
What does a GeckoLib ClassNotFoundException mean?
It means the game tried to use GeckoLib code but could not find GeckoLib. Add one correct GeckoLib file for Forge 1.20.1 to your mods folder and try again.
What if I have two Verity files in my mods folder?
Remove the extra copy. Keep only one Verity .jar for Java 1.20.1, because duplicates can clash and crash the game.
Why does Verity load but never speak?
That is usually a missing or badly pasted Groq API key, not a crash. Check the key in the mod settings, paste it in full, and follow the Java Edition guide for full detail.