Fix VMware Could Not Open /dev/vmmon on Linux (No Need to Disable Secure Boot)
7Are you getting this error in VMware Workstation or Player on Ubuntu or Lubuntu?
Failed to initialize monitor device.
Could not open /dev/vmmon: No such file or directory.
Please make sure that the kernel module `vmmon` is loaded.
This happens when Secure Boot blocks VMware’s vmmon and vmnet kernel modules because they are not signed.
📌 Commands used in this video:
sudo vmware-modconfig --console --install-all
sudo apt install build-essential linux-headers-$(uname -r)
1️⃣ Install required packages
sudo apt update
sudo apt install mokutil openssl
2️⃣ Create signing key
mkdir -p ~/vmware-signing
cd ~/vmware-signing
openssl req -new -x509 -newkey rsa:2048 -keyout MOK.priv -outform DER -out MOK.der -nodes -days 36500 -subj "/CN=VMware Module Signing/"
3️⃣ Enroll key with Secure Boot (MOK)
sudo mokutil --import MOK.der
👉 Set a password and reboot.
👉 In the blue MOK Manager screen: Enroll MOK → Continue → Yes → Enter password → Reboot
4️⃣ Find VMware module locations
modinfo -n vmmon
modinfo -n vmnet
5️⃣ Sign the modules (replace paths if different)
sudo /usr/src/linux-headers-$(uname -r)/scripts/sign-file sha256 ~/vmware-signing/MOK.priv ~/vmware-signing/MOK.der /lib/modules/6.14.0-27-generic/misc/vmmon.ko
sudo /usr/src/linux-headers-$(uname -r)/scripts/sign-file sha256 ~/vmware-signing/MOK.priv ~/vmware-signing/MOK.der /lib/modules/6.14.0-27-generic/misc/vmnet.ko
6️⃣ Reload modules
sudo modprobe -r vmmon vmnet
sudo modprobe vmmon
sudo modprobe vmnet
7️⃣ Verify modules are loaded
lsmod | grep vmmon
lsmod | grep vmnet
✅ With this fix, VMware will run perfectly on Ubuntu or Lubuntu without turning off Secure Boot.
If this video helps you, don’t forget to Like 👍, Subscribe 🔔, and Comment below if you have any issues — I reply to all!
I