8 Ways to Fix Nexus Mod Manager Won’t Open (Updated)


PC Games have revolutionized the gaming industry. And a significant factor towards achieving that is the third party gaming mods. Dota 2 and Half-life 2 mods even to this day and age are considered legends, so much so that they went on to become standalone games later on. Nexus Mod Manager is a program that allows game mods to be installed and modified on the system. With over 200 supported game mods and 10 million registered users, it is one of the most extensive game mod programs available for PC. So, you can understand the frustration when the Nexus Mod Manager Won’t Open.

If you too have come across such situations, you need not worry. Here are a few nifty tricks to help fix your problem of nexus mod manager not opening.

How to Fix Nexus Mod Manager Won’t Open Error

Check for proper version of .NET Framework

Sometimes the method could be as simple as having the right release of .NET Framework Version 4 on your PC. If you have installed the latest build of Nexus Mod Manager 0.61.6, then you need to install the proper version of .NET Framework 4.6.

.NET Framework 4
.NET Framework 4

Nexus Mod Manager won’t open if you are still running older version of .NET Framework.

Run Nexus Mod Manager as an administrator

Before jumping on to any complicated steps to solve nexus mod manager won’t launch, you might want to try some simple tweaks to try and see if that solves your problem. If you suddenly started to get Nexus Mod Manager Won’t Open error, this could be due to a new update.

Nexus Mod Manager
Nexus Mod Manager

First of all, try running the Nexus Mod Manager as an administrator. This should fix the problem of nexus mod manager not working. To do this, right-click on the Nexus Mod Manager client and click Run as Administrator. NMM might fail to open when you have installed a new update and to execute those files, Administrator privilege is required.

See also: 16 Ways to Fix Steam Won’t Open Error in Windows

Must read: 3 Ways to Fix NVIDIA Control Panel Won’t Open Error

See also: 10 Methods to Fix Google Chrome Won’t Open Error

Run in compatibility mode

If your system is running the latest Windows 10 and the Nexus Mod Manager Won’t Open, you should try the compatibility settings to see if reverting to an old version of the OS helps.

To do this you can directly click on Troubleshoot Compatibility by right-clicking on the NMM icon, or you can do it manually:

  • Right-click on the Nexus Mod Manager client on the desktop.
  • Select Properties.
  • Click on the compatibility tab.
compatibility tab in nexus mod manager
compatibility tab in nexus mod manager
  • Select Windows 8 in compatibility mode.
  • Hit Apply and OK.

It should fix your problem of nexus mod manager won’t launch. If the problem still isn’t resolved, move on to the next step.

Delete the user config file

You can try this if your nexus mod manager won’t start. The config file associated with the game profile might have been corrupted, and you might have to set up a new config file.

It happens when you have downloaded a mod for a new game, and that runs in conflict with your previous games. You can delete the config file associated with the Nexus Mod Manager client.

Don’t worry about doing this won’t delete your save game data. Browse to the following folder on your system:

C:/Users/Your name/AppData/Local/Black_Tree_Gaming/NexuxClient.exe…../version number(0,63.13.0)/user.config

It won’t affect your existing games or mod profiles; you will just have to get the start menu again for all the games individually.

Delete previous contents

  • Go to your Nexus Mod Manager Destination drive. You can find the folder.


  • If you aren’t able to find AppData folder, you need to tick show hidden files and folders under files and other options for solving nexus mod manager wont open.
  • Now make a backup of the NexusClient.exe_Url folder and place it somewhere else on your PC.
Backup NMM folder
Backup NMM folder
  • Then delete all contents of the Black Tree Gaming folder. Then re-launch Nexus Mod Manager. It should open and start looking up for games installed on your PC. If another error pops up on the screen about exceptions, just hit “continue” and it should keep working.

Check your antivirus for issues

Often the culprit why Nexus Mod Manager Won’t Open could be your antivirus software which might probably be blocking some of the critical files required for the execution of Nexus Mod Manager to work.

Add Antivirus Exclusion for NMM
Add Antivirus Exclusion for NMM

You can do this by temporarily disabling your anti-virus system or add NMM to the whitelist or adding the program exe into the exceptions list.

Downgrade your Nexus Mod Manager

If you have installed a new update, it might be the reason why the nexus mod manager not opening. It usually occurs when a new update file wasn’t installed correctly, or it is not compatible with the system. To fix this, try to revert to an older version of Nexus Mod Manager. You can get the old files form here.

Fresh Install of NMM

If none of the above help and Nexus Mod Manager Won’t Open, you could try and do a fresh install of Nexus Mod Manager. Before doing this, note down the version, installation information and the virtual install path of each game.

  • Uninstall Nexus Mod Manager.
  • Select to remove all contents and settings when asked.
  • Go to Run.
  • Type “regedit”.
  • Go to edit>find and type NMM.
  • Delete all the files associated with NMM.
  • Reinstall Nexus Mod Manager.

Hopefully, this should fix the issue of nmm won’t open and get Nexus Mod Manager started again. If, however, all of these steps fail, your only hope is to do a clean install of Windows. But you better hope it doesn’t come to that!


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