To troubleshoot many common WordPress issues, you will need access to your site’s files, preferably through something like FTP or sFTP, but you could use a web interface for a File Manager, if need be. DO NOT rely on the built-in WordPress editor.
“My site just suddenly broke, but I didn’t touch anything.”
If nothing on your site or server changes, your website will not just suddenly stop working. A problem arises from a cause. Did you update your theme? Did you update a plugin? If you haven’t touched your site, reach out to hosting support to confirm there isn’t a hosting issue. If you need developer assistance, knowing the last steps taken before the issue happened can save a lot of time.
The “Read Your Error Messages” Story
With the exception of the PHP white screen of death, most errors trigger a helpful message that identify what the error is. They may even call out the problematic plugin, file or issue.
404 Not Found: All Subpages
THE ISSUE
Your website homepage is working but clicking to any subpage is triggering a 404 error. Your pages are in the backend… what gives?!
THE SOLUTION
Go to Settings > Permalinks and resave your permalinks.
Error Establishing Database Connection
THE ISSUE
None of your site is accessible and all anyone sees on any page is this error message.
THE SOLUTION
Check your database settings in your wp-config file. Check with your hosting company to see if they are having MySQL server issues.
Syntax Errors
All of these errors will display with a start of “Syntax Error: [details on error]” They typically do include filename. Most commonly they are triggered by copying & pasting code from the web into your theme and either there is an inherent issue in the code or you missed part of the code snippet or similar. However, they can occasionally be caused by a plugin or theme update. The error message provides a clue on where to look.
Stuck in Maintenance Mode
THE ISSUE
Your site is displaying a maintenance message but you’re not doing any maintenance.
THE SOLUTION
Delete the .maintenance file from your site install’s root directory.
Cannot upload media files or broken images
Every time you try to upload media to your site, you get a permission denied error.
SOLUTION:
The permissions of your uploads folder may need to be adjusted on your host to be writeable (744 permissions or 755 if still having issues.) Contact your host for assistance on changing folder permissions, if necessary.
PHP White Screen of Death
THE ISSUE
Your site is displaying… nothing. A complete white screen of nothingness.
THE SOLUTION
Almost always caused by PHP code errors or memory exhaustion. Try deactivating all plugins, increasing memory limits or turn on WP DEBUG.