Minecraft not working: 12 causes and fixes

1. Java isn't installed or is the wrong version

Minecraft Java Edition is written in Java and needs the right version of the JRE (Java Runtime Environment) to run. Since version 26.1, the game requires Java 25 (this applies to all 26.x versions). Versions 1.21.x (from June 2024) need Java 21 or newer. Earlier versions of the game (1.18-1.20.4) require Java 17, and even older ones (1.16 and earlier) run on Java 8.

Microsoft's official Minecraft Launcher includes a built-in Java and downloads the right version automatically. The problem shows up when:

• You use an alternative launcher (MultiMC, Prism Launcher, GDLauncher) and haven't set the Java path
• You have several Java versions installed and the system PATH variable points to the wrong one
• The official launcher is corrupted and doesn't download the runtime
• You set the path to javaw.exe in the profile by hand, but that Java version is too old

How to fix it

1. Open the command prompt (press Win+R, type cmd, press Enter) and type:

   java -version

   You need to install a newer Java if you see a version lower than required (25 for 26.x, 21 for 1.21.x), for example 1.8.0_xxx, 17.0.x (or 21.0.x when you play 26.x), or if you get the message 'java' is not recognized.
2. Download Adoptium Temurin 25 (a free, open-source Java distribution; Temurin 21 is enough for 1.21.x) from adoptium.net. Choose the JRE (not the JDK, unless you're a programmer) and Windows x64, then install it with the Set JAVA_HOME variable option checked.
3. If you use an alternative launcher, set the Java path in its settings:
   • Prism Launcher: Settings → Java → Auto-detect → pick Temurin 21
   • MultiMC: Settings → Java → Browse → point it to C:\Program Files\Eclipse Adoptium\jre-21\bin\javaw.exe
4. Restart the launcher and try again.

2. Outdated graphics card drivers

Minecraft requires OpenGL 4.4 or newer (since version 1.17). Older GPU drivers may not support the required OpenGL version, which causes a black screen or a crash. This is the second most common cause of Minecraft launch problems, especially after Windows updates, which can overwrite your GPU driver with a generic Microsoft driver.

Never rely on Windows Update for GPU drivers. Windows installs generic versions that are stable but often outdated. You need to download the drivers straight from your graphics card's manufacturer.

How to fix it

1. Check which graphics card you have: press Win+R, type dxdiag and go to the Display tab. Note down the card's name and manufacturer.
2. Download the latest drivers from the manufacturer's website:
   • NVIDIA: nvidia.pl/Download (choose "Game Ready Driver")
   • AMD: amd.com/support (AMD Software: Adrenalin Edition)
   • Intel (integrated graphics): Intel Driver & Support Assistant
3. Install the driver and choose Clean Install: this removes the old driver and installs the new one from scratch.
4. Restart your computer (logging out isn't enough!) and launch Minecraft again.

Special case: a laptop with two graphics cards. Many laptops have integrated Intel graphics plus a dedicated NVIDIA/AMD card. Minecraft may use the weaker Intel chip by default. To fix that:

• NVIDIA: NVIDIA Control Panel → Manage 3D settings → Program Settings → add javaw.exe → "High-performance NVIDIA processor"
• AMD: AMD Software → Gaming → Add a game → Graphics profile: High performance
• Windows 11: Settings → System → Display → Graphics → javaw.exe → High performance

3. Your antivirus is blocking Minecraft

Antivirus programs (especially Avast, Norton, McAfee, Kaspersky and Bitdefender) can mistakenly flag Minecraft or Java files as a threat. It's a common problem because Minecraft downloads and runs .jar files, which looks suspicious from an antivirus point of view: .jar files can contain malware, and the antivirus heuristics react to that behavior.

The problem gets worse when:

• You've recently updated your virus definitions
• You've installed mods (.jar files downloaded from the internet)
• You use Forge or Fabric (a modded game)
• You have "real-time protection" turned on with aggressive heuristics

How to fix it

1. Add exclusions in your antivirus for these locations:

   C:\Users\YourName\AppData\Roaming\.minecraft
   C:\Program Files (x86)\Minecraft Launcher
   C:\Program Files\Eclipse Adoptium\jre-21\bin\javaw.exe
   C:\Program Files\Java\jre-21\bin\javaw.exe

   Replace YourName with your Windows username.
2. Restore files from quarantine. Open your antivirus, go to the Quarantine/Threat history section and restore every file related to Java or Minecraft.
3. For specific antivirus programs:
   • Avast: Menu → Settings → General → Exceptions → Add Exception → enter the paths above
   • Norton: Settings → Antivirus → Scans and Risks → Items to Exclude from Auto-Protect
   • Kaspersky: Settings → Threats and Exclusions → Manage exclusions → Add
   • McAfee: Real-Time Scanning → Excluded Files → Add file
4. Test: Temporarily turn off your antivirus's real-time protection and launch Minecraft. If the game works, the problem is confirmed. Add the exclusions and turn the protection back on.

4. Corrupted game files

Minecraft files can get corrupted for many reasons: an interrupted download, the computer shutting down during a game update, disk damage, faulty RAM (which causes random bit flips in files) or an aggressive antivirus deleting parts of the game. The damage can affect the Java libraries, resource files (textures, sounds, models), the launcher's assets or the game's .jar file itself.

How to fix it

1. Method 1: force a fresh download (official launcher):
   • Open the Minecraft Launcher
   • Go to the Installations tab
   • Click the three dots icon next to the profile that doesn't work
   • Choose Edit
   • Click More Options
   • Uncheck Resolution (if it's set to a custom value) and save
   • The launcher automatically verifies the files and downloads the missing ones the next time you launch the game
2. Method 2: delete the version files by hand:

   %appdata%\.minecraft\versions\

   Delete the folder of the problem version (for example 1.21.5). The launcher downloads it again.
3. Method 3: full reset (keeps your worlds and mods):
   1. Press Win+R and type %appdata%\.minecraft
   2. Copy the saves (worlds), resourcepacks, screenshots and mods folders to a safe place
   3. Delete the whole .minecraft folder
   4. Start the launcher, which downloads the whole game from scratch
   5. Paste the saved folders back

5. Too little RAM allocated

By default the Minecraft Launcher gives the game 2 GB of RAM. That's enough for vanilla Minecraft on low settings, but it falls short when:

• You play with mods (Forge/Fabric with 20+ mods can need 4-6 GB)
• You use big resource packs (512x, 1024x)
• Your render distance is set to 16+ chunks
• You load big worlds with lots of entities
• You use shaders (Iris/OptiFine + shaders = more RAM needed)

Before you give Minecraft more RAM, check how much you have in total. Press Ctrl+Shift+Esc (Task Manager) and go to the Performance → Memory tab. If you have 8 GB of RAM or less, don't give Minecraft more than half: the system and other programs need memory too.

How to fix it

1. Open Minecraft Launcher → Installations.
2. Click the three dots next to the profile → Edit → More Options.
3. In the JVM Arguments field, find the -Xmx2G parameter and change it to:

   -Xmx4G

   Recommended values:
   Vanilla: 2-4 GB With mods (up to 50): 4-6 GB Large modpacks (100+): 6-8 GB With shaders + HD packs: 4-8 GB
4. Don't allocate too much! Giving Minecraft 16 GB, for example, can paradoxically hurt performance: the Java garbage collector then needs longer pauses, which causes micro-stuttering. 4-6 GB is optimal for most setups.
5. For advanced memory management, use the arguments from our guide: Optimal JVM arguments for Minecraft.

6. Mod conflicts

Mods are the most common cause of Minecraft crashes when the game used to work fine. The problems can come from:

• Version incompatibility: a mod made for 1.20.x used on 1.21.x
• Missing dependencies: the mod needs another mod (for example Fabric API, Cloth Config, Architectury)
• Conflicts between mods: two mods change the same game mechanic
• Mixing APIs: a Forge mod used with Fabric Loader or the other way around
• A corrupted mod .jar file: an unfinished download

How to fix it

1. Quick method: test without mods:
   1. Go to %appdata%\.minecraft
   2. Rename the mods folder to mods_backup
   3. Launch Minecraft: if it works, one of the mods is the culprit
2. Elimination method: find the problem mod:
   1. Create an empty mods folder
   2. Move mods from mods_backup to mods one at a time (or five at a time)
   3. Launch the game after each addition: when it crashes, the mod you added last is the culprit
3. Read the crash log: Open the file from the crash-reports/ folder and look for the line with Caused by:, which usually contains the name of the problem mod. Paste the log on mclo.gs, and the site identifies the problems automatically.
4. Check compatibility: On Modrinth or CurseForge, every mod lists the Minecraft versions it supports and the dependencies it needs. Make sure all your mods are for the same game version and loader (Forge OR Fabric/Quilt, don't mix them).

7. Windows Defender / SmartScreen is blocking the launch

Even if you don't have a third-party antivirus, Windows Defender (built into Windows 10/11) can block Minecraft. The problem gets worse when you have Controlled folder access (ransomware protection) turned on: this feature stops unknown programs from writing files to protected locations, which keeps Minecraft from saving your world, settings and logs.

How to fix it

1. Open Windows Security (search for it in the Start menu).
2. Go to Virus & threat protection → Virus & threat protection settings → Manage settings.
3. Scroll down to Exclusions → Add or remove exclusions and add:
   • Folder: C:\Users\YourName\AppData\Roaming\.minecraft
   • Process: javaw.exe
   • Folder: C:\Program Files (x86)\Minecraft Launcher
4. If you have Controlled folder access turned on:
   • Windows Security → Virus & threat protection → Ransomware protection
   • Click Allow an app through Controlled folder access
   • Add javaw.exe and Minecraft Launcher.exe
5. SmartScreen: If you see a SmartScreen warning while installing the launcher or a mod, click "More info" → "Run anyway". SmartScreen blocks programs that don't have a digital signature from a trusted publisher.

8. Missing Visual C++ Redistributable

Visual C++ Redistributable is a set of Microsoft libraries that many programs need, including the new Minecraft Launcher and Bedrock Edition. They usually install automatically along with other games or programs, but cleanup tools (CCleaner, IOBit) or a "system cleanup" can remove them.

This problem mainly affects Bedrock Edition (from the Microsoft Store) and the new Minecraft launcher. The Java Edition game itself doesn't need VC++ (it runs on Java), but the launcher does.

How to fix it

1. Download the Visual C++ Redistributable (both x64 and x86) from Microsoft:

   https://aka.ms/vs/17/release/vc_redist.x64.exe
   https://aka.ms/vs/17/release/vc_redist.x86.exe

2. Install both versions (x64 and x86), even on a 64-bit system. Some programs need the 32-bit version.
3. If the problem continues, install the older versions too: 2013 and 2012 from Microsoft's official page.
4. Restart your computer and try again.

9. 32-bit Java on a 64-bit system

32-bit Java can address ~1.5 GB of RAM at most, no matter how much your computer physically has or how much you allocate in the JVM arguments. That's too little even for vanilla Minecraft in newer versions, and with mods it's nowhere near enough.

This happens when you have 64-bit Windows (the standard for years) but installed the 32-bit version of Java (often marked "x86" or "i586" in the installer's name). Alternative launchers that don't include a built-in Java are especially prone to this.

How to check

In the command prompt, type:

java -version

Look for 64-Bit Server VM at the end. If you see 32-Bit or no architecture information at all, you have the 32-bit version.

How to fix it

1. Uninstall your current 32-bit Java: Control Panel → Programs → Uninstall a program → find "Java" (there may be several entries) and uninstall all the 32-bit versions.
2. Download and install 64-bit Java 25 (for 26.x; Java 21 is enough for 1.21.x) from adoptium.net:
   • Operating system: Windows
   • Architecture: x64
   • Type: JRE
   • Version: 21 (LTS)
3. During installation, check Set JAVA_HOME variable and Add to PATH.
4. In the launcher, set the path to the new Java (if it isn't detected automatically):

   C:\Program Files\Eclipse Adoptium\jre-21.0.x-hotspot\bin\javaw.exe

10. Firewall rules are blocking the connection

Minecraft needs an internet connection to authenticate your Microsoft/Mojang account, download skins and resource packs, connect to multiplayer servers and check for updates. If a firewall blocks the network traffic of Java, Minecraft or the launcher, you'll get login or multiplayer problems.

This applies to Windows Firewall as well as third-party firewalls (Comodo, ZoneAlarm, ESET Firewall) and routers with strict rules.

How to fix it

1. Windows Firewall:
   1. Open Control Panel → System and Security → Windows Defender Firewall
   2. Click Allow an app or feature through Windows Defender Firewall
   3. Click Change settings (requires administrator rights)
   4. Find Java Platform SE Binary on the list and check Private and Public
   5. If Java isn't on the list, click Allow another app → Browse → point it to javaw.exe
   6. Repeat for Minecraft Launcher
2. Advanced rules: If that didn't help, open Windows Defender Firewall with Advanced Security (wf.msc) and check whether any outbound rules block javaw.exe or MinecraftLauncher.exe.
3. Router/company network: If you play on a school or company network, the administrator may have blocked these ports:
   • Port 443 (HTTPS: login and downloads)
   • Port 25565 (the default Minecraft server port)
   In that case, you have to ask the administrator to unblock them or use a different network.
4. Test: Temporarily turn off the firewall (netsh advfirewall set allprofiles state off in cmd run as administrator) and check whether Minecraft logs in. If it does, add allow rules and turn the firewall back on.

11. Corrupted launcher profile

The Minecraft Launcher stores your profile configuration, login data and settings in JSON files in the .minecraft folder. These files can get corrupted by a sudden shutdown of the program, conflicts with other apps or disk errors. The problem especially affects Microsoft's new launcher (installed from the Store or the Xbox app), which has a notorious history of bugs.

How to fix it

1. Reset the profiles file:
   1. Close the Minecraft Launcher (make sure it isn't running in the background: check Task Manager)
   2. Go to %appdata%\.minecraft
   3. Rename the launcher_profiles.json file to launcher_profiles.json.bak
   4. Start the launcher, which creates a new profiles file
   5. Your worlds and mods stay untouched, but you'll have to recreate your installation profiles
2. Reset Microsoft's new launcher (Windows 10/11):
   1. Open Settings → Apps → Installed apps
   2. Find Minecraft Launcher
   3. Click the three dots → Advanced options
   4. Click Repair first. If that doesn't help, click Reset
3. Alternative: use a different launcher. If Microsoft's new launcher keeps causing trouble, consider Prism Launcher (open source, free, supports Microsoft accounts). It's more stable and gives you full control over Java versions and mods. Get it from our page: Download Minecraft.

12. Incompatible hardware

Since version 1.17, Minecraft has required OpenGL 4.4, which rules out very old graphics cards. On July 21, 2026, Microsoft raised the official Java Edition requirements for the first time in 17 years, and the graphics card now has to support Vulkan 1.3. The game should still launch on weaker hardware, but without any guarantee of smooth play, and with the move from OpenGL to Vulkan some older cards and integrated chips may lose support. The current Minecraft Java Edition requirements (as of October 2026):

How to check your graphics card

1. Press Win+R, type dxdiag and press Enter
2. Go to the Display tab
3. Note down the card's name and driver version
4. Check whether the card supports OpenGL 4.4 and Vulkan 1.3 (for example on TechPowerUp GPU Specs)

What to do if your hardware is too weak

• Play an older version: Minecraft 1.16.5 and older only need OpenGL 2.1, so they run on practically any hardware from the last 15 years. Create a separate profile in the launcher with version 1.16.5.
• Bedrock Edition: Bedrock (Windows 10/11) is optimized for weaker computers. If you've bought Java Edition, you can get Bedrock for free (check minecraft.net/profile).
• Minecraft Education: The education edition has lower hardware requirements.
• Mesa OpenGL (Linux): On Linux, the Mesa library can emulate higher OpenGL versions on older hardware. Run Minecraft with MESA_GL_VERSION_OVERRIDE=4.5.

Quick cheat sheet: what to check first

If you don't have time to read the whole guide, here are 5 steps that solve 90% of problems:

1. Check the logs: %appdata%\.minecraft\logs\latest.log and crash-reports/. The log tells you exactly what's wrong.
2. Update your GPU drivers from the manufacturer's website (not Windows Update!).
3. Remove your mods: rename the mods folder to mods_backup and check whether vanilla works.
4. Increase RAM: in the JVM arguments, change -Xmx2G to -Xmx4G.
5. Reinstall Java: download Adoptium Temurin 21 x64 and uninstall the old versions.

Frequently asked questions

Other problems and related guides

This guide covers Minecraft launch problems. If the game starts but you have other problems, check our other guides:

Still no fix? Share the contents of your latest.log file (ideally via mclo.gs) and describe your problem on our forum (in Polish), where the community is happy to help.

Summary

Minecraft launch problems almost always come down to one of the 12 causes above. In 90% of cases it's enough to update your GPU drivers, install the right Java version, add antivirus exclusions or fix mod conflicts. The key to a quick fix is reading the logs: the latest.log file tells you exactly what caused the problem.

If none of the solutions above helped, consider:

• A full reinstall: uninstall Minecraft and the launcher, delete the .minecraft folder (after backing up your worlds!) and install from scratch
• An alternative launcher: Prism Launcher is more stable than Microsoft's official launcher
• A hardware check: use MemTest86 to test your RAM and CrystalDiskInfo to check your disk
• Contacting Mojang support: help.minecraft.net

We update this guide after every major Minecraft release. Last updated: October 28, 2026 (Java and hardware requirements for 26.x). The rest of the advice applies to Minecraft 1.21.5 and Bedrock 1.21.60.