Linux NetworkManager Error — No Network Connection Fix

What Does This Error Mean?

NetworkManager is the service that manages Wi-Fi and Ethernet connections on most Linux desktop distributions. When it fails, you lose internet access and may see errors like 'NetworkManager is not running' or 'device not ready.' Restarting the NetworkManager service fixes most issues, but a bad driver or configuration can require more work.

Affected Models

Ubuntu
Debian
Fedora
Linux Mint
Pop!_OS
openSUSE

Common Causes

The NetworkManager service has crashed or was accidentally stopped
The network interface driver (for Wi-Fi or Ethernet) is missing or incompatible with the current kernel
A configuration file for a network connection has become corrupted
A recent kernel update broke compatibility with a proprietary Wi-Fi driver
The network interface is being managed by a different service, causing a conflict with NetworkManager

How to Fix It

Restart the NetworkManager service. Open a terminal and run: sudo systemctl restart NetworkManager. Wait 10 seconds, then check if your network connection has returned.

This is the fastest fix for a crashed NetworkManager. It is the equivalent of turning networking off and on again.
Check if NetworkManager is running. Run: sudo systemctl status NetworkManager. If it shows 'inactive' or 'failed,' enable and start it: sudo systemctl enable NetworkManager && sudo systemctl start NetworkManager

On some minimal installations, NetworkManager may not be enabled to start automatically. This command enables and starts it.
Check which network interfaces are available. Run: ip link show or nmcli device status to see all network interfaces and their states.

If your Wi-Fi card does not appear in the list at all, the driver is missing. If it shows 'unavailable,' the driver is loaded but not working.
Reinstall Wi-Fi drivers. On Ubuntu with Broadcom Wi-Fi: sudo apt install bcmwl-kernel-source. For general additional drivers: sudo ubuntu-drivers install

Many laptop Wi-Fi cards require proprietary firmware that is not installed by default. The ubuntu-drivers tool finds and installs the correct driver for your hardware.
Delete corrupted network connection profiles. Connection profiles are stored in /etc/NetworkManager/system-connections/. Run: ls /etc/NetworkManager/system-connections/ to see them. Delete any that look wrong: sudo rm /etc/NetworkManager/system-connections/[filename].nmconnection

A corrupted connection profile can cause NetworkManager to fail when trying to connect. Deleting it and reconnecting creates a fresh profile.

When to Call a Professional

Network problems on Linux are almost always fixable with terminal commands. If your Wi-Fi card requires a proprietary driver that is not working, you may need to use an Ethernet cable to install the driver. A Linux professional can help with complex driver installation on systems without wired network access.

Frequently Asked Questions

How do I connect to Wi-Fi from the terminal without NetworkManager?

If NetworkManager is not available, use the wpa_supplicant tool. Run: sudo wpa_supplicant -B -i wlan0 -c /etc/wpa_supplicant/wpa_supplicant.conf to connect. Then: sudo dhclient wlan0 to get an IP address. This is more complex than NetworkManager but works without a graphical interface.

What is the difference between NetworkManager and ifupdown?

NetworkManager is the modern, dynamic approach — it handles network connections for desktop use and can switch between Wi-Fi networks automatically. ifupdown is the older static approach — you configure connections in /etc/network/interfaces and bring them up manually. Most desktop Linux distributions use NetworkManager today.

My Ethernet works but Wi-Fi does not show up at all. What is wrong?

If Wi-Fi is completely absent (not even listed in ip link show), the Wi-Fi driver is not loaded. Run: lspci | grep -i wireless to identify your Wi-Fi chip, then search for the correct driver. On Ubuntu, try: ubuntu-drivers devices to see recommended drivers for your hardware.