Common WordPress errors and how to fix them

Most WordPress errors come from a handful of causes: a plugin or theme that breaks after an update, wrong database details, too little memory, or a damaged configuration file. Each has a known fix. This article lists the errors site owners meet most, with the fix for each in a line and a link to the step-by-step guide, so you can recover quickly or know when to ask for help.

Two rules before you fix anything

Take a backup first. Many fixes involve renaming folders or editing files. A backup of the files and the database means a fix that goes wrong costs nothing.

Find the real error. Since WordPress 5.2, a fatal error shows visitors a "technical difficulties" screen and emails the site's administrator a link to recovery mode, in which the faulty plugin or theme is paused so you can log in and deal with it. For more detail, WordPress's debug log records the error: turn on WP_DEBUG and WP_DEBUG_LOG in wp-config.php, keep WP_DEBUG_DISPLAY off so visitors never see it, read wp-content/debug.log, and switch debugging off again when you are done. WordPress itself describes these settings as meant for testing, not for a live site left running.

The errors, and their fixes

"There has been a critical error on this website", or a blank white screen

Usually: a plugin or theme failing, often after an update. Fix: use the recovery-mode link from the administrator's email, or deactivate plugins by renaming the plugins folder over FTP or the file manager, then switch to a default theme if that is not enough. Guide: How to fix common WordPress errors.

Internal Server Error (500)

Usually: a damaged .htaccess file. Fix: rename .htaccess, then save Settings > Permalinks to write a fresh one. If that is not it, deactivate plugins, switch theme, or reinstall the core files. Guide: How to manually reinstall WordPress core.

Error establishing a database connection

Usually: the database name, user, password or host in wp-config.php no longer match the database. Fix: check the four values against the database in your control panel. If they are right, ask your host whether the database server is reachable. Guide: How to change your WordPress database password.

Allowed memory size exhausted

Usually: a plugin or task needing more memory than PHP allows. Fix: raise WP_MEMORY_LIMIT in wp-config.php. It cannot go above the limit your hosting sets for PHP. Guide: PHP error: allowed memory size exhausted.

Pages return 404 after a change

Usually: the rewrite rules for permalinks are missing or out of date. Fix: open Settings > Permalinks and select Save Changes without changing anything. WordPress rewrites the rules.

"Briefly unavailable for scheduled maintenance"

Usually: an update that stopped halfway. Fix: delete the .maintenance file in the site's root folder, then check that the update completed. Guide: How to force reinstall or update a plugin without losing data.

"Sorry, this file type is not permitted for security reasons"

Usually: WordPress allows only certain file types to be uploaded. Fix: upload a permitted type, or allow the type deliberately and safely. Guide: How to fix the "file type is not permitted" error.

"Missing a temporary folder"

Usually: PHP has no usable temporary folder for uploads. Fix: give PHP a temporary folder it can write to. Guide: How to fix the "Missing a Temporary Folder" error.

The login page keeps reloading

Usually: cookies, a wrong site address, or a plugin. Fix: clear the site's cookies, check that the WordPress and site addresses match the address you use, and rename the plugins folder to rule out a conflict. Guides: How to log in to the WordPress dashboard and How to reset an admin password via phpMyAdmin.

"Too many redirects"

Usually: the site address and the HTTPS settings disagree, so the browser is sent round in a circle. Fix: make sure the WordPress and site addresses use the same form of the address (with or without www, and https), and that only one place forces HTTPS. Guide: How to install a free Let's Encrypt certificate in Plesk.

Permission errors on upload or update

Usually: file and folder permissions changed by a migration or a manual upload. Fix: reset files and folders to the permissions WordPress expects. Guide: How to reset WordPress file and directory permissions.

Fixes that live in the hosting panel

Some errors are fixed in your hosting control panel rather than in WordPress: the PHP version, PHP's memory and upload limits, and the site's certificate. On Noiz Premium shared hosting you can change the PHP version of a website in Plesk. Legacy plans run a fixed PHP version.

Most errors are avoidable

The same few causes sit behind most of these errors: updates applied without a restore point, plugins left to age, and changes made on the live site. A routine of backups before updates, regular updates, and a test after each one prevents most of them.

When to ask for help

Open a ticket if the site holds orders or bookings, if a fix needs changes you are not comfortable making, or if the error points to a compromise. If you would rather not do this at all, WordPress Care is Noiz doing the work: weekly updates of WordPress, themes and plugins with a restore point taken first and a rollback if an update breaks something, checks after every cycle, security patching, and clean-up and restore if the site is hacked. It works on a Noiz hosting service or on a site hosted elsewhere.

Sources

Checked 19 October 2026.

WordPress

• Common WordPress errors
• Debugging in WordPress
• Fatal error recovery mode in WordPress 5.2
• Editing wp-config.php
• Logging in
• HTTPS
• upload_mimes filter

Noiz

• How to Fix Common WordPress Errors and the guides linked above
• WordPress Care

Note: while some of this content was produced with the help of AI, the final editing has been done by a real human being.