Troubleshooting

Fixing 404 Not Found errors: causes and how to fix

A 404 error means the requested page does not exist on the server. Learn how to check document roots...

Beginner 5 min Troubleshooting June 2026

Disk quota exceeded-what to do

When your hosting account runs out of disk space, email stops working and file uploads fail. This gu...

Beginner 6 min Disk Troubleshooting June 2026

DNS resolution issues-causes and troubleshooting

Fix DNS resolution errors when domain won't load. Check nameservers, DNS propagation, cache, CNAME r...

Beginner 11 min Troubleshooting DNS June 2026

404 error-file not found pages and fixes

Fix 404 errors when files are deleted, URLs changed, or misconfigured. Create custom 404 pages and i...

Beginner 9 min HTTP Errors Links June 2026

PHP max execution time-increase timeout for long scripts

Increase PHP max_execution_time limit for long-running scripts, imports, or batch processing....

Beginner 8 min Timeout PHP June 2026

PHP memory limit exceeded-increase and optimize

Fix \"Allowed memory size exhausted\" errors. Increase PHP memory limit, identify memory hogs, optimiz...

Beginner 10 min PHP Errors Memory June 2026

My website is loading slowly-what to check

Diagnose the cause of a slow website: heavy plugins, missing caching, oversized images, resource lim...

Beginner 7 min Performance Troubleshooting June 2026

My website is down-what to check first

A fast triage checklist for diagnosing a downed site: DNS, server status, SSL errors, account suspen...

Beginner 7 min Troubleshooting DNS June 2026

Fixing a 403 Forbidden error: permission denied solutions

A 403 error means the server understood the request but refused to allow access. This UnderHost guid...

Intermediate 6 min Troubleshooting 403 June 2026

Fixing a 500 Internal Server Error

A 500 error means the server encountered an unexpected problem. This UnderHost guide shows how to fi...

Intermediate 7 min Troubleshooting 500 June 2026

Connection refused errors-causes and fixes

Fix \"connection refused\" errors when connecting to FTP, SSH, or databases. Firewall issues, port blo...

Intermediate 10 min Troubleshooting Network June 2026

Troubleshooting slow connection to your server or website

A systematic approach to diagnosing slow website or server connections: test your internet speed, ru...

Intermediate 7 min Troubleshooting Network June 2026

Error establishing a database connection-diagnosis and fix

Fix the \"Error Establishing a Database Connection\" in WordPress and other PHP applications. Covers w...

Intermediate 7 min MySQL Troubleshooting June 2026

Domain not resolving-DNS troubleshooting guide

Your domain is not loading even though the server is online. Step-by-step DNS troubleshooting: check...

Intermediate 7 min Troubleshooting DNS June 2026

Fixing a 502 Bad Gateway error

A 502 Bad Gateway means your web server failed to respond. Diagnose upstream server issues, PHP-FPM ...

Intermediate 6 min Troubleshooting HTTP Errors June 2026

Fixing a 503 Service Unavailable error

503 error means the server is temporarily unavailable. Diagnose maintenance mode, overload, or servi...

Intermediate 5 min Troubleshooting HTTP Errors June 2026

504 Gateway Timeout-causes and fixes

Fix 504 Gateway Timeout errors. Slow PHP scripts, long database queries, resource overload, upstream...

Intermediate 12 min HTTP Errors Troubleshooting June 2026

HTTP 520 error-web server is down or unreachable

Fix CloudFlare 520 errors when origin server is down, unreachable, or timing out....

Intermediate 11 min HTTP Errors CloudFlare June 2026

PHP Fatal Errors-causes and how to debug

Fix PHP fatal errors: undefined function, memory limit, allowed memory exhausted, syntax errors in W...

Intermediate 11 min PHP Errors Debugging June 2026

Headers already sent error-diagnosis and fix

Fix \"headers already sent\" PHP error. Remove whitespace, BOM, or redirect code before output....

Intermediate 8 min PHP Error PHP June 2026

Out of Memory Errors: Diagnose and Fix OOM Killer

Fix out of memory (OOM) errors on Linux VPS. Identify memory leaks, optimize processes, configure OO...

Intermediate 12 min Memory System June 2026

PHP Parse Errors-syntax mistakes and fixes

Fix \"Parse error: syntax error\" in PHP. Missing semicolons, braces, quotes, and debugging parse erro...

Intermediate 10 min Syntax Errors PHP June 2026

Permission denied errors-chmod, chown, and fixes

Fix \"Permission denied\" errors with chmod, chown, and file ownership on Linux/VPS servers....

Intermediate 10 min File Permissions Linux June 2026

Redirect loop error-fix infinite redirects

Fix \"too many redirects\" or \"redirect loop\" caused by misconfigured .htaccess, HTTPS, or plugin conf...

Intermediate 10 min Redirect Error Links June 2026

508 Resource Limit Reached-what it means and how to fix it

A 508 error means your hosting account hit its CloudLinux CPU or entry process limit. What triggers ...

Intermediate 6 min Troubleshooting Shared Hosting June 2026

Session timeout-users logged out unexpectedly

Fix users getting logged out. Increase session timeout, fix browser cache, check server time, clear ...

Intermediate 10 min Sessions Timeout June 2026

SSL Certificate Errors-browser warnings and fixes

Fix SSL certificate errors: untrusted, expired, domain mismatch, mixed content, self-signed certific...

Intermediate 11 min SSL Errors June 2026

Timeout errors-diagnosis and resolution

Fix timeout and connection errors. DNS timeouts, connection refused, socket timeouts, PHP execution ...

Intermediate 10 min Network Errors Timeout June 2026

How to run a traceroute (tracert) for network diagnostics

Traceroute maps the path data takes from your computer to a server. Run it on Windows, Mac, or Linux...

Intermediate 6 min Troubleshooting Network June 2026

Undefined function error-called function doesn't exist

Fix \"Call to undefined function\" when function file not loaded, plugin inactive, or extension missin...

Intermediate 9 min PHP Error Functions June 2026

Whitespace before output-causes and fixes

Fix whitespace output before headers, cache issues, and invisible text in PHP files....

Intermediate 9 min PHP Error Output June 2026

Zero-Size File Errors: Diagnose and Fix Empty Files

Debug zero-size files on VPS. Identify causes: disk full, partial uploads, crashes. Find and fix emp...

Intermediate 10 min Errors Debugging June 2026