Black screens after login, missing WiFi connections, and software rendering mode messages signal driver issues that can disrupt daily work on Linux Mint. These problems often stem from graphics drivers (especially with NVIDIA hardware), network adapters, or kernel mismatches. Addressing these issues requires a methodical approach, starting with system updates and progressing to driver management and secure boot configuration.

Update and Prepare Your System

Begin by updating all system packages. This ensures you’re working with the latest bug fixes and compatibility improvements for drivers and kernel modules. Open a terminal and run:

sudo apt update && sudo apt upgrade

This command refreshes your package list and upgrades installed software. Reboot after the update completes to load any new kernel or driver modules.

Install or Reinstall Graphics Drivers

Graphics driver issues, especially with NVIDIA hardware, frequently cause black screens, low-resolution displays, or the “Running in software rendering mode” error. Linux Mint’s Driver Manager usually recommends the best driver, but Secure Boot and kernel changes can prevent proper loading.

Launch Driver Manager from the application menu. Allow it to scan your hardware and present available drivers. For NVIDIA cards, select the recommended proprietary driver (avoid the “open” variant unless you need open-source support for specific reasons).

Apply the driver selection and follow any on-screen prompts to complete installation. When prompted, reboot your system.

If you see a black screen or the driver does not load (e.g., nvidia-settings shows no details), Secure Boot may be blocking the driver. Secure Boot is a UEFI firmware feature that only allows signed kernel modules to load. To allow the NVIDIA driver, you must enroll a Machine Owner Key (MOK).

During driver installation, if prompted, create a new MOK password. On reboot, the system will display a blue screen for MOK enrollment. Use the password you set to enroll the key. This authorizes the driver to load with Secure Boot enabled.

After enrolling the MOK, boot into Linux Mint and confirm the driver is active. In a terminal, check:

lsmod | grep nvidia

If there’s no output, the driver is not loaded. Double-check Secure Boot status with:

mokutil --sb-state

If Secure Boot is still causing issues and you require it only for Windows, consider temporarily disabling it in UEFI settings, as Windows 11 can run with Secure Boot off. Re-enable it after troubleshooting if necessary.

Address Kernel and Compiler Mismatches

Driver installation can fail if the system’s kernel and compiler (GCC) versions do not match. This is especially common after upgrading the kernel or system packages.

Check the kernel’s GCC version by examining the build logs or using:

cat /proc/version

Compare with your installed GCC version:

gcc --version

If they differ, upgrade GCC to match the kernel’s build version:

sudo apt install gcc-12

Replace gcc-12 with the required version. After updating, reinstall the driver using Driver Manager.

Fix WiFi and Network Adapter Issues

Missing WiFi networks or failed connections often indicate missing or misconfigured drivers for your wireless adapter.

Confirm your WiFi device is detected:

lspci | grep -i network

lsusb

If your device appears, but networks are missing, reinstall the network manager:

sudo apt-get install --reinstall network-manager

For persistent issues, check Driver Manager for proprietary drivers related to your wireless hardware and apply the recommended choice. Reboot after changes.

Address Software Rendering Mode and Low Resolution

When Linux Mint runs in software rendering mode or displays at a low resolution, the graphics driver isn’t loading. This can result from Secure Boot, failed driver installation, or kernel/driver mismatches.

Verify which driver is active:

inxi -G

If the output lists llvmpipe or nouveau instead of nvidia, the proprietary driver is not loaded.

Return to Driver Manager, ensure the proprietary driver is selected, and confirm MOK enrollment if Secure Boot is on. If you continue to see issues, try switching to an older kernel from the GRUB boot menu, as newer kernels sometimes break compatibility with certain drivers.

For persistent failures, temporarily switch to the open-source nouveau driver, which prioritizes compatibility over maximum performance. This can restore normal display functionality while you continue troubleshooting.

Resolve Black Screen After Driver Installation

Blank screens after installing a proprietary driver are usually caused by Secure Boot blocking the driver or by incompatible driver versions.

Access a virtual terminal using Ctrl + Alt + F1 (or F2 to F6). Log in with your username and password.

Remove the problematic driver:

sudo apt remove --purge nvidia*

Reboot. The system should now use the open-source driver, restoring display access. You can then retry the proprietary driver installation, ensuring Secure Boot and MOK steps are followed.

Check and Sign Kernel Modules for Secure Boot

With Secure Boot enabled, unsigned kernel modules—including proprietary drivers—are blocked. Signing modules and enrolling the MOK is essential for the driver to load.

After installing the driver, if you are not prompted to create a MOK, you can manually sign the module. Generate a signing key:

openssl req -new -x509 -newkey rsa:2048 -keyout MOK.priv -outform DER -out MOK.der -nodes -days 36500 -subj "/CN=Custom MOK Module Signing/"

Import the key with:

sudo mokutil --import MOK.der

Set a password when prompted. Reboot, and follow the blue MOK enrollment screen to finish the process. This authorizes the driver module to load with Secure Boot active.

Sign the NVIDIA kernel module using your private key. Replace nvidia.ko with the actual module path:

sudo /usr/src/linux-headers-$(uname -r)/scripts/sign-file sha256 MOK.priv MOK.der /path/to/nvidia.ko

After completion, reboot to verify the driver loads successfully.

Additional Troubleshooting Tips

Switching kernels: If a new kernel causes issues, select an older kernel from the GRUB boot menu to restore functionality.
Monitor driver status: Use inxi -G or nvidia-smi to check if the NVIDIA driver is loaded and the GPU is recognized.
Use Timeshift: Create system snapshots before major changes. This allows quick restoration if a driver update or kernel change causes boot problems.
Consult logs: Review /var/log/syslog or dmesg for error messages related to drivers or kernel modules.

Resolving driver issues in Linux Mint restores full hardware performance and system stability. Keeping drivers, kernels, and system packages updated, while understanding Secure Boot and MOK requirements, prevents most recurring problems.