Guides about troubleshooting
- Fix apt and dpkg errors on Ubuntu and Debian Each common apt or dpkg error message, what it means and the command that fixes it, without deleting lock files or forcing packages. Intermediate 15 min
- Linux server does not boot: emergency mode, fsck and kernel fixes When SSH never comes back after a reboot, the console shows why. Match the message on the screen to one of the cases below and follow its fix. Advanced 20 min
- Fix Windows Update problems on Windows Server When Windows Update fails or hangs, the cause is usually low disk space, a damaged component store or a stuck update cache. Work through the fixes in order and choose how updates are installed. Intermediate 30 min
- Nested virtualization problems: KVM, Hyper-V, WSL 2 and emulators When a hypervisor, WSL 2 or an emulator says virtualization is not available, check the server type first, then the component that is missing. The common messages and their fixes, for Linux and Windows. Intermediate 15 min
- macOS server troubleshooting: access, sleep, keychain and Xcode Most problems on a HyperDC Mac fall into a few groups: reaching the desktop, keeping the Mac awake, signing over SSH or in CI, and Xcode's simulators and disk use. Symptoms, causes and fixes. Intermediate 15 min
- GPU troubleshooting: nvidia-smi errors, CUDA mismatches and memory Most GPU failures come down to the kernel module, the driver version or GPU memory. Read the exact message, match it below and apply the fix, from a reboot to a driver change. Intermediate 15 min
- Replace a failed disk in Linux software RAID (mdadm) When a RAID 1 member fails, the server keeps running on the other disk. Find the failed disk, take it out of every array, ask us to replace it, then copy the partition layout and let the array rebuild. Advanced 40 min
- MetaTrader on a VPS: troubleshooting connections and Expert Advisors When an Expert Advisor stops trading, the cause is usually the connection, the automated-trading switches or a terminal that was closed. Check each in turn with the terminal's own logs. Beginner 15 min
- Android emulator troubleshooting: virtualization, Hyper-V and graphics Emulators fail for a handful of reasons: missing hardware virtualization, a hypervisor conflict, graphics settings or too few resources. Match your symptom and apply the fix. Intermediate 15 min
- Fix 500, 403, 404 and 508 errors on web hosting Every website error has a cause written in a log. Open the error log in cPanel or Plesk, then match the error code to the usual causes: a broken .htaccess, file permissions, PHP, or the account's resource limits. Intermediate 15 min
- Fix common WordPress errors Most WordPress errors come from a plugin, a theme, the database settings in wp-config.php or a PHP limit. Turn on the debug log to see the cause, then follow the fix for the message you see. Intermediate 20 min
- Fix ASP.NET and IIS errors on Windows hosting IIS errors carry a sub-code that names the cause: 500.19 is a configuration problem, 500.30 and 500.31 a start-up or runtime problem. Read the code, turn on the stdout log for ASP.NET Core or detailed errors for ASP.NET, fix the cause and turn logging off again. Intermediate 20 min
- Internet radio troubleshooting in SonicPanel Most radio problems have a simple cause: the AutoDJ is offline, the encoder uses the wrong protocol or port, uploads hit the disk limit, or a setting delays a playlist. Match your symptom below and check the setting it names in SonicPanel. Beginner 15 min
- Fix SSL certificate errors and HTTPS warnings Browser warnings name the cause. Check which names, dates and issuer the served certificate has, then fix the matching problem: a missing name, an expired certificate, a missing chain, a wrong binding, a redirect loop or insecure page content. Intermediate 15 min