How To Fix Monster Hunter: World (MHW) Error Code 51-mw1?

Trouble launching your copy of Monster Hunter: World on PC? Getting a ’51-mw1′ error code that won’t go away? This guide will walk you through the most common fixes to resolve error 51-mw1 in MHW and get you back to hunting monsters in no time.

How To Fix Monster Hunter: World (MHW) Error Code 51-mw1?

Monster Hunter: World ’51-mw1′ errors typically indicate an issue connecting to the game’s servers. However, the problem may also be caused by faulty game files or software conflicts on your PC. Here are the top troubleshooting tips to try:

Restart Your Network Devices/PC

The first step is to simply restart your network hardware and PC. This refreshes all connections and services which often resolves transient connection issues:

  • Restart your network router, modem, access points, and other hardware
  • Reboot your PC

After restarting devices, launch MHW again to see if the error persists.

Check Firewall/Antivirus Software

Overly aggressive security software can sometimes block apps from accessing the Internet. Temporarily disable any firewalls, antivirus programs, or other security tools on your PC and try MHW again.

Re-enable protection after testing and if the game works, you’ll likely need to adjust some software settings to allow MHW network access.

Run the Microsoft Network Troubleshooter

The Network Troubleshooter is a built-in Windows tool that can automatically detect and resolve many common network errors.

To run the troubleshooter:

  1. Open Windows Settings
  2. Go to Update & Security > Troubleshoot
  3. Select Internet Connections
  4. Click Run the Troubleshooter and follow any steps

After completing troubleshooter steps, relaunch MHW to test the error.

Renew/Flush DNS

Outdated DNS records can interfere with connecting to MHW servers. Flushing DNS refreshes these so try:

  1. Open Command Prompt as admin
  2. Run ipconfig /flushdns to flush DNS
  3. Run ipconfig /registerdns to refresh DHCP registration

Launch MHW after running these commands to see if 51-mw1 persists.

Modify Hosts File

Editing the Hosts file overrides DNS to map hostnames to IP addresses. Try mapping Capcom domains locally:

  1. Launch Notepad as admin
  2. Open C:\Windows\System32\Drivers\etc\hosts
  3. Add lines for Capcom domains mapped to

# etc.

Save hosts changes and relaunch MHW. If no improvement, undo Hosts file edits.

Reset Winsock Catalog

Resetting the Winsock catalog clears out old settings/data and reinitializes core networking components in Windows.

To reset Winsock:

  1. Open Command Prompt as admin
  2. Run netsh winsock reset
  3. Restart your PC

After rebooting, check if MHW connects without error 51-mw1.

Repair/Reinstall Monster Hunter: World

If you’ve tried the above with no success, corrupted game files may be the culprit. Validate files through Steam to check for errors, or reinstall MHW completely if needed:

  • Steam > Right-click MHW > Properties > Local Files tab > Verify Integrity of Game Files
  • Steam > Right click MHW > Manage > Uninstall

Relaunch after repairing files or reinstalling to see if error 51-mw1 persists in the game.

Update Windows, Drivers, DirectX

Outdated Windows updates and software components like drivers or DirectX can sometimes break certain games.

Ensure your system is entirely up to date by trying the following:

  • Install latest Windows updates
  • Update GPU/other device drivers
  • Download/install newest DirectX components

Check if updates resolve Monster Hunter connectivity issues after restarting your PC.

Adjust Router MTU

If you have an unusual home network setup, incompatible router MTU values may prevent connecting to MHW properly.

Attempt fixing this by:

  1. Log into your WiFi router admin interface
  2. Locate MTU setting (e.g. in Advanced Options)
  3. Reduce value to 1400-1450 and Save changes
  4. Restart router and connected PCs

Lowering MTU sizes can resolve some connection issues caused by ISP networks. Test if MHW works after tweaking this router value.

Key Takeaways for Fixing MHW Error 51-mw1

  • Restart networking devices/PC first to refresh all connections
  • Temporarily disable firewalls/security tools interfering with game
  • Use built-in Windows Network Troubleshooter to fix common issues
  • Flush DNS, alter Hosts file to override faulty name resolutions
  • Reset Winsock catalog to reinitialize networking components
  • Validate/reinstall game files if corrupted data causes problems
  • Update Windows, GPU drivers, DirectX software just in case
  • Adjust router MTU sizes if unusual home network setup

Stuck on a particular fix or still seeing error 51-mw1? Leave a comment below!


Error 51-mw1 stopping you from enjoying Monster Hunter: World on PC can be frustrating. But in most cases, the problem stems from temporary network/connectivity issues that can be easily fixed with some targeted troubleshooting steps.

Start with simpler solutions like rebooting devices or using built-in Windows tools. Then escalate to resetting networking components, reinstalling game files, or updating software as needed. Tweaking router MTU values can also help resolve the error for unusual home network configurations specifically.

With the fixes above, you should be able to troubleshoot MHW error 51-mw1 stopping you from getting into hunts. Let us know if any steps resolve things for you or if the error persists so we can help further! Happy hunting!

Frequently Asked Questions

  1. What causes the 51-mw1 error code in Monster Hunter: World?
    51-mw1 errors in MHW are typically caused by an inability to connect properly to the game’s servers. This could stem from temporary network problems, faulty game files, firewall conflicts, and various other issues.
  1. Where can I find error logs for the 51-mw1 MHW problem?
    Event Viewer > Windows Logs > Applications can contain debug information about why Monster Hunter: World failed to launch with the 51-mw1 error code. Capcom may also request dxdiag or other diagnostics.
  1. Does the 51-mw1 error affect Monster Hunter: World on Xbox/PlayStation consoles too?
    No – 51-mw1 connectivity issues appear exclusive to the PC version of Monster Hunter: World at this time. The error does not widely affect console players.
  1. Can having Comodo Firewall installed cause the 51-mw1 error even if disabled?
    Yes, there are a few reports of Comodo Firewall interfering with MHW even when supposedly disabled. Fully uninstalling it may be required as a troubleshooting step for 51-mw1 errors.
  1. If my friend can connect to MHW fine on the same Internet connection, does that rule out network issues for 51-mw1?
    Not necessarily – if your friends uses a wired connection and you use WiFi for example, that could cause sufficient differences resulting in the 51-mw1 error on your end alone. Always still check for problems on your PC.
  1. I tried everything but still have the Monster Hunter: World 51-mw1 error. What should I do?
    In rare persistent cases where no troubleshooting fixes 51-mw1 for MHW, your best recourse may be backing up game data and doing clean OS reinstall if corrupt Windows system files turn out to be the culprit.
  1. Is Monster Hunter: World error 51-mw1 a known issue with Windows 11 or 10 updates?
    Some Windows builds have caused sporadic reports of 51-mw1 connectivity failures. Check actual Windows update history and forums to pinpoint any particular problematic patches to avoid. Rollback may help.
  1. Can Special K mod cause the 51-mw1 error when launching Monster Hunter: World?
    Yes – mods like Special K can sometimes conflict with anti-cheat protections used in Monster Hunter: World. Test fully removing all mods if 51-mw1 issues arise after installing any unofficial mods or injections.
  1. How can I contact Capcom support for help fixing Monster Hunter: World error 51-mw1?
    You can submit a support ticket detailing your 51-mw1 connection issues through Capcom’s Help Center website for troubleshooting by their support team as needed.
  1. Does Port Forwarding fix the 51-mw1 error for Monster Hunter: World?
    In some cases yes – properly setting up Port Forwarding on your router to unblock the required ports for Monster Hunter: World can resolve error 51-mw1 problems stemming from blocked connectivity.
  1. What networkingports should I open on my router tofix MHW error 51-mw1?
    Capcom recommends opening/forwarding TCP ports 80, 443, 20002, 30840, 30850, and 30870 on your router to ensure proper connectivity for resolving 51-mw1 errors in Monster Hunter: World.
  1. Can using a VPN cause Monster Hunter: World error51-mw1?
    Yes – actively running a VPN while attempting to connect to Monster Hunter World’s servers can trigger 51-mw1 connectivity issues in some instances. Try disconnecting the VPN as a troubleshooting step.
  1. Does editing the Hosts file to block Capcom domains help fix MHW error 51-mw1?
    No – blocking Capcom server domains via Hosts file edits typically makes 51-mw1 issues worse or fail to launch entirely, as this prevents connecting to required servers. Remove any added domain blocks from Hosts file.
  1. Can my ISP be blocking Monster Hunter: World connectivitycausing error 51-mw1?
    Potentially yes – some strict ISPs do block certain gaming ports/protocols which could manifest as 51-mw1 connection errors with Monster Hunter: World servers. Call your ISP to request removing blocks for the required MHW ports/addresses.
  1. I can login to other games fine but still get error 51-mw1 in Monster Hunter: World – why?
    The connectivity requirements and servers for each game differ – so while you can access other games, something specific to Monster Hunter: World’s architecture or current status could be triggering the 51-mw1 error currently.
  1. Does restarting my router fix Monster Hunter: World error 51-mw1?
    Simply rebooting consumer routers can resolve transient connectivity issues, so yes – restart your router (leave unplugged for 1 minute) as well as connected PCs to refresh networking stack and try fixing 51-mw1 instances.
  1. Can enabling UPnP on my router help resolve Monster Hunter: World connectivity issues and error 51-mw1?
    It’s worth a shot – UPnP automates port forwarding on routers, helping avoid manual configuration issues that could cause problems reaching Monster Hunter: World servers, potentially triggering error 51-mw1.
  1. Does uninstalling VPN software help resolve Monster Hunter: World 51-mw1 errors?
    Uninstalling VPN clients removes lingering TAP adapter artifacts which can conflict, so yes – fully removing Nord, Express, or other VPN software as part of troubleshooting 51-mw1 connectivity issues can help in some cases.
  1. Where is the network troubleshooter in Windows Ican use to try and fix MHW error 51-mw1?
    The built-in Network Troubleshooter for diagnosing connectivity issues is located in Windows 10/11 Settings under Update & Security > Troubleshoot > Additional troubleshooters > Internet Connections.
  1. Why does Monster Hunter: World error 51-mw1 happen intermittently with no pattern?
    If 51-mw1 only occurs sporadically, transient problems like brief ISP network blips, server hiccups, home router firmware bugs, or game updates may be triggering the temporar connectivity issues. Try replicating when failures happen.

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