How to Solve could not open /dev/vmmon: Broken Pipe Vmware Fusion on macOS Catalina

When you try opening a virtual machine for the first time, after installing VMWare Fusion in a fresh installation of OS X, you may get the error “Could not open /dev/vmmon: Broken Pipe. After that a message like this appeared; Failed To Initialize Monitor Device. How to solve it? Here, let us discuss it.


Cannot start a virtual machine Starting Virtual Machine in Fusion.


To enable kernel extensions by manually enabling them and then allow Virtual Machines to boot up.


This error occurs on MacOS Catalina, Mojave and High Sierra because Apple needs the third Party Kernel extensions to be enabled manually.

Impact / Risks

If the Security and Privacy System Preferences is not changed to let the application’s kernel extensions to load, VMWare Fusion is will be able to show error when you are starting a virtual machine.


  • You have to launch “Disk Utility” tool from LaunchPad.
  • Make sure Macintosh HD is highlighted and click First AID.
  • After the First AID is complete, shutdown the Mac (not restart) and boot it up.

How to Solve could not open dev vmmon Broken Pipe Vmware Fusion on macOS Catalina

How to Solve could not open /dev/vmmon: Broken Pipe

Now, you are able to launch VMware Fusion and then follow the steps explained below.

  • At the first step, you have to navigate to System Preferences -> Security & Privacy on the host macOS Catalina (or High Sierra and Mojave).
  • Under the General tab towards the bottom of the window, you are going to see error with option to click on Allow.
  • Now, you have to click Allow.

For note: You need the admin Privileges to allow the application.

If the error persists, follow the steps explained below.

  • Please launch Terminal and Run the command: sudo kextload -b /Applications/VMware\*Then, you are able to repeat the first step to the third step.
  • Manually uninstalling VMware Fusion and reinstall it. In this case, simply you are able to repeat the first step to the third step.

Also, you are able to delete the MacOS quarantine from the Fusion.dmg if the error persists. To do that, you are able to follow these below.

  • Firstly, you have to uninstall VMware Fusion manually.
  • After that, you are able to download a fresh copy of VMware Fusion.
  • Please make sure that the installer file of VMware Fusion (.dmg) is not mounted on Mac OS X.
  • Now, you have to go To Terminal on Mac from Finder -> Go -> Utilities.
  • Afterwards, you have to run the first command.
  • Then, you have to run the second command
  • Please run the command in the fifth step to confirm the removal.
  • Lastly, you are able to install VMware Fusion by using the downloaded installer file of VMware Fusion (.dmg).

Until this, we are sure that you understand what you should do when you are having the error of Broken Pipe. As we explained above, to allow the security restrictions for VMware Fusion application, you only need to go to your System Preferences. To do that, you are able to click the apple icon at the top of the menu bar. Then, you are able to click allow the application to load, if it is blocked under General tab. Please allow the application to control the computer under Privacy tab, to save changes only click on the Padlock at the bottom. Now all done, just power up your Virtual Machine.

Based on the research, this error message is due to the VMware kernel extension not being approved for use. This requires to approve kexts (kernel extensions) was introduced in macOS 10.13 High Sierra. You are going to need to manually approve this kext in order for VMware Fusion to operate correctly. If you see this message, once again you only need to navigate to System Preferences, select Security & Privacy, and then approve VMware’s kernel extension by choosing the ‘allow’ option. To do this, you have to make sure that you click the padlock icon on the bottom left of the window to allow the changes. What do you do if you do not see the button to allow the kernel extension? In some cases, after installing VMware Fusion, the button to allow the kernel extension to be used cannot appear. For this case, you are able to approve kernel extensions by booting into recovery mode. Here are steps to do that:

  • At the first step, you have to startup the Mac in recovery mode..
  • After that, you are able to click the Utilities menu and then choose Terminal.
  • Now, you have to enter the command below:

/usr/sbin/spctl kext-consent add EG7KH642X6

  • The next step that you have to do is to press Enter.
  • Lastly, you only need to close the Terminal app, and restart.

About VMware Fusion

VMware Fusion is a software from VMware which virtualizes Windows operating systems and application programs, so they are able to be used on Mac computers. It is a trusted virtualization solution with deep customization options and integration features for running Windows. One of VMware Fusion features; Unity view, it allows a virtualized application to appear in the Mac OS desktop. Based on the research, VMware released VMware Fusion 1.0 on August 6, 2007. VMware released VMware Fusion 6.0 on September 3, 2013 to become compatible with latest Mac operating system. It is slower than competitor Parallels Desktop in testing, but it has a better-balanced feature set.


  • It is a flexible virtualization solution for expert and professional users.
  • Reliable and trusted performance.
  • Useful and easily modified default settings.
  • It support (Official and unofficial) for almost any Intel-based operating system.


  • It run slower than Parallels or VirtualBox in testing.
  • It has not Parallels’ Rollback feature for kiosk-style emulated systems.

That’s an explanation regarding the error of broken Pipe Vmware Fusion on macOS Cataline and how to solve it.

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