Linux & Unix

Kernel errors, dependency hell, permission issues, systemd units.

125 solutionsPage 1 of 6
Sort by: Newest Most Viewed A-Z

Chrome OS install fails: the three things that actually fix it

Chrome OS install bombs most often from bad USB sticks, missing UEFI settings, or image errors. Here...

Intermediate 7 views May 31, 2026
command not found

Fix 'bash: command not found' on Linux (PATH reset fix)

When bash can't find a command, it's usually a broken PATH or missing package. Here's how to fix it ...

Beginner 7 views May 30, 2026
sudo: unable to resolve host <hostname>

Fixing 'sudo: unable to resolve host' on Linux

A quick fix for the 'sudo: unable to resolve host' error. You'll fix your /etc/hosts file or hostnam...

Beginner 6 views May 30, 2026
Permission denied

Linux 'Permission Denied' Error: 3 Quick Fixes

You see 'Permission denied' when running commands or accessing files. Usually it's wrong file permis...

Beginner 7 views May 30, 2026
Permission denied

Fixing 'Permission Denied' on sudo: Why It Happens and How to Fix It

That 'permission denied' on sudo usually means your user isn't in the sudoers file. Here's the quick...

Beginner 5 views May 30, 2026
sudo: unable to resolve host <hostname>

Fix 'sudo: unable to resolve host' in Ubuntu 22.04 LTS

This error pops up when sudo can't match your hostname to an IP. It's a DNS issue, not a sudo one. F...

Beginner 5 views May 29, 2026
ERR_TOO_MANY_REDIRECTS

Fix infinite redirect loop after search click on Nginx

When clicking search results causes a redirect loop or stalling, it's usually a misconfigured rewrit...

Intermediate 1 views May 29, 2026
permission denied

Fix 'permission denied' for /var/run/docker.sock on Ubuntu 22.04

You try running Docker without sudo and get a permission denied error on /var/run/docker.sock. It me...

Beginner 5 views May 29, 2026
umount: target is busy.

Fix 'umount: target is busy' on Linux USB drive

The kernel says the USB mount point is in use. Start with the lazy unmount, then find the culprit pr...

Intermediate 4 views May 29, 2026
bash: command not found

Fixing 'bash: command not found' on Linux – What Actually Works

PATH issues or missing packages cause this. Check your PATH first, then install the package. Don't w...

Beginner 4 views May 29, 2026

Fix Google search redirect loop on Linux: kill cookies & session storage

Google search redirect loop on Linux usually means corrupted cookies or session storage. The fix is ...

Intermediate 2 views May 29, 2026
Permissions 0644 for '/home/user/.ssh/id_rsa' are too open.

Fix 'Permission Denied' on SSH Key: chmod 600 Isn't Working

SSH rejects your key if anyone else can read it. Here's the exact fix and why OpenSSH is so touchy a...

Beginner 7 views May 29, 2026

Fix 'Permission denied' on Linux when running shell scripts

Running a shell script with 'Permission denied' usually means the execute bit is missing. Here's how...

Beginner 6 views May 29, 2026
301 redirect loop

Nginx redirect loop: how to fix the 301 redirect cycle on Linux

A 301 redirect loop happens when your Nginx config sends the client in a circle. Here's how to trace...

Intermediate 3 views May 29, 2026
chmod: invalid mode

Fixing 'chmod: invalid mode' when setting permissions on symlinks

Getting 'invalid mode' when trying to chmod a symlink? It's not a typo—chmod has specific rules for ...

Intermediate 6 views May 29, 2026
mount: /mnt: special device /dev/sdb1 does not exist

Fix 'mount: /mnt: special device /dev/sdb1 does not exist'

Gets you past the 'special device does not exist' error when mounting drives on Linux. Covers wrong ...

Beginner 9 views May 29, 2026
bash: command not found

Fix 'bash: command not found' on Linux in 2 Minutes

The PATH variable got corrupted or empty. Quick fix: export PATH=/usr/local/sbin:/usr/local/bin:/usr...

Beginner 5 views May 29, 2026
Permission denied (publickey)

Fix 'Permission Denied' for SSH Key on Linux (chmod 600)

SSH keys need strict permissions. If they're too open, SSH flat-out refuses them. Quick chmod fix, t...

Beginner 4 views May 28, 2026
Permission denied (publickey)

Linux 'Permission Denied' fix for SSH public key login

This error happens when SSH public key auth fails. Usually it's bad permissions on .ssh or authorize...

Intermediate 4 views May 28, 2026
Permission denied (publickey)

Fix: Permission denied (publickey) in SSH on Linux

SSH rejects your key because permissions on ~/.ssh or its contents are too open, or the wrong key is...

Beginner 8 views May 28, 2026
W: GPG error: ... NO_PUBKEY <key>

ChromeOS Linux: 'W: GPG error' on apt update — fix 2025

When ChromeOS Linux container's apt update fails with missing GPG keys, it's usually because the con...

Beginner 8 views May 28, 2026
Permission denied

Fix 'Permission denied' when running sudo commands on Ubuntu 22.04

You're locked out of sudo on Ubuntu 22.04. The fix is checking /etc/sudoers syntax and ensuring your...

Intermediate 6 views May 28, 2026
Invalid class name

Fix 'Invalid class name' error in Linux shell scripts

This error pops up when a shell script tries to use a Java class name with bad formatting. Here's ho...

Beginner 4 views May 28, 2026

Fix 'Permission denied' in Linux when running scripts with ./

Getting 'Permission denied' when you try to run a script with ./? The fix is almost always adding ex...

Beginner 4 views May 28, 2026