How can you debug theme errors in WordPress?

As a suggestion: always use "WP_DEBUG_LOG" because if you use "WP_DEBUG" WordPress will display all of your website errors in front-end of your website and will make your website messy and makes visitors uncomfortable when they visiting your site. But if you use "WP_DEBUG_LOG" you will have a file that have errors in it and your website visitors will not see website errors.

Debugging theme errors in WordPress is essential for troubleshooting issues and ensuring that your website functions correctly. Here are the steps to debug theme errors in WordPress: Enable WP_DEBUG: In your WordPress wp-config.php file, set WP_DEBUG to true. This will enable debugging mode and display error messages on your site. Find the following line and make sure it's set to true: Visit your website's frontend to see if any error messages or warnings are displayed. Check the Backend: Check the Error Log: Use Debugging Plugins: Deactivate Plugins: Switch to a Default Theme: Check Theme Files: Check Theme Settings: Inspect Browser Console: Contact Theme Developer or Support: Backup Your Site:

My personal preference is to use the Query Monitor plugin rather than using the debug log as it will work for most situations. It's efficient and easy to use and will help you catch PHP warnings and errors, slow SQL queries and more.

Practically it's not always OK to have WP_DRBUG_LOG as true for Big Websites especially with big woocommerce stores having thousands of products, becuase probably the WP Log file getting too much big (in one of my case which I examined, it exceeds 45 GB). So my suggestion is to enable it only at the time of diagnosis and troubleshooting and then disable it again.

Starting my journey as a young front-end developer, I soon grasped the importance of WordPress's Debug Mode. Think of it as the 'X-ray vision' of your site, illuminating underlying issues. Activating it is a breeze: dive into your wp-config.php file and flip the 'WP_DEBUG' switch from false to true. But, it doesn’t stop there! Consider also enabling 'WP_DEBUG_LOG'. This nifty feature logs errors, acting as a detailed diary of mishaps. These logs, stored in the wp-content directory, are goldmines of information, pivotal in the debugging process. As someone passionate about React.js, I appreciate tools that make problem-solving transparent and efficient.

Throughout my adventures in web development, I've found that, akin to detectives, developers also have their trusty logs. In WordPress, the 'debug.log' file is our magnifying glass. Nestled within the wp-content directory, this log chronicles the who, what, and where of every error. Accessing it is straightforward using FTP or your hosting panel’s file manager. It's like having a detailed timeline of events. Each error entry provides key info: the timestamp, file origin, exact line, and a description. So, next time your theme acts up, remember to consult this 'journal'. It might just have the clues you're seeking!

I have just commented on a different article. I say this to so many developers, become friends with log files. Understand them, how they are structured, how to navigate them and find issues, how to set logging levels in your particular stack. I have lost count of the amount of times that devs working for me have been struggling to solve issues, my first port of call is always logs, 99.9% of the time iI find the issue within minutes and dev understands and solves the issue.

Venturing into WordPress as a React.js enthusiast, I quickly understood that plugins, while powerful, can sometimes clash like superheroes in a crossover event. When theme errors rear their head, a likely suspect could be a rogue plugin. The remedy? Temporarily de-powering these plugins. Head over to your dashboard, navigate to 'Plugins', and start the deactivation process. You can go all out and deactivate everything, or play detective, deactivating one by one to identify the misbehaving plugin. Once you pinpoint the troublemaker, you can decide its fate: an update or a farewell. Debugging, like development, is all about iteration and insight!

Deactivate plugins one by one to identify if any are causing theme errors. Review the theme's code, particularly in the functions.php and style.css files, for errors.

Sometimes it happens, some plugin may break your website, and if you try to access it in the browser it will be not accessible, so you can debug this by deactivating the plugins one by one.

To avoid the risk of breaking your live website, it is a good practice to create a staging environment, which is a copy of your live site on a separate server. You can then test any changes you want to make to your live site on the staging environment first. Once you are satisfied with the changes, you can then deploy them to your live site.

7 Recreate htaccess file. It's located in the root of your wordpress site. Delete it and create it again from Dashboard-> setting -> permalinks and on save changes to create a new. What is the htaccess file & Why do we need to create it again? The .htaccess is a distributed configuration file, and is how Apache handles configuration changes on a per-directory basis. WordPress uses this file to manipulate how Apache serves files from its root directory, and subdirectories thereof. Most notably, WP modifies this file to be able to handle pretty permalinks. We need to create it again because Sometimes You may encounter a white page on your website and Check all things but you've In this case recreate htaccess file.

Check for Syntax Errors Syntax errors in your theme's code can cause issues. Verify that all the PHP, HTML, CSS, and JavaScript code in your theme's files is correctly formatted and free from syntax errors.