[WP] Analysis and Solutions for Common WordPress Installation, Running, and Usage 500 Errors

Common analysis and solutions for 500 internal error in WordPress installation, operation, and usage

Recently, I wrote a blog post about my experience solving a WP issue and posted it on However, some friends were still unable to solve the problem after reading it, and they left comments on my blog. In this post, I will share several PHP 500 Error situations and their solutions that I have encountered. If you are able to solve the problem using these methods, please leave a comment.

First, let me explain what a 500 internal Error is. It is a server-side internal error with an error code of 500. There are multiple reasons for this error, and it is not as scary as it sounds. In many cases, it is just a security measure taken by the server. For example, if there is a script parsing error or any other abnormality, the server may return a 500 error. This article mainly discusses these related errors. I once tried uploading a phpinfo() without a semicolon, and it resulted in a direct 500 error instead of a PHP error code and prompt asking me to check for missing semicolons. If your hosting provider has this kind of setup, then encountering 500 errors in the future will be common.

Now, I will share several errors that I have experienced:

  1. When installing WordPress, after the upload is complete, I encounter a 500 error when entering the installation page.

This is the most frustrating situation, and there are many reasons for it. I will provide a few that I have experienced, which can be categorized as follows:

A. Using a non-official version or an unstable version of WP, or a version that has been modified by yourself. In general, downloading a stable version directly from the internet and reinstalling it should solve the problem.

B. Some virtual hosts only support PHP4 or lower versions, and some PHP extensions are not supported. Currently, WP requires at least PHP 4.0 or higher. I recommend checking the installation requirements of WP by running phpinfo() before installing it. If the requirements are not met, consider changing your hosting provider.

  1. After filling in all the installation options and saving my installation information, I encounter a 500 error and cannot access the installation page again.

This is the most common situation during installation. Please check reasons A and B mentioned earlier. If they are satisfied, it might be due to the following:

C. Database connection problem. The default MySQL address for most hosts is localhost, but it is not excluded that it could be a different IP address. If the IP address is entered incorrectly, the database cannot be connected, and PHP throws an error, resulting in a server-side 500 error. Also, incorrect username and password can cause a 500 error. I recommend checking the config.php file you uploaded to verify if the database address and user password are valid.

D. File permission problem. During the installation of WP, some installation files may be modified. If the permissions are insufficient or you do not have the necessary permissions, the modification will fail, resulting in a failed installation and a server-side 500 error. What's more frustrating is that some hosts may consider your modification request as potentially damaging to other users' files, and they may directly restrict your directory's PHP interpretation permissions. No matter how you check or modify it, it won't work. My suggestion is to directly contact the administrator, and they will help you resolve the issue. Therefore, for your hosting provider, first, you must have sufficient permissions, and second, you must ensure that the uploaded files are not set as read-only.

E. .htaccess problem. Some WP installation packages include this file, which is used to configure access permissions and store other IIS configuration information. If you do not have sufficient server permissions, one situation is that the file becomes invalid, and any modifications you make will be ineffective. Another situation is that the server directly disables your script permissions, resulting in a 500 or 404 error. This situation usually occurs on Windows hosts. I recommend confirming if you have the relevant permissions first before installing. Additionally, I suggest deleting this file, uploading it, and then modifying the 404 error configuration in the host's control panel.

  1. After installing or deleting WP plugins or configuring plugins, I encounter a 500 error.

There are many reasons for this type of error, but in general, simply deleting the plugin should solve the problem. If it still doesn't work, you can directly contact the administrator.

G. Plugin installation requirements issue. Some plugins require a higher version of WP. I recommend upgrading or searching for other suitable versions online. Also, for other extension support such as Perl scripts or Python scripts, I recommend checking if your server has installed these supports by running PHPinfo().

H. Unofficially recognized plugin issue. Usually, these plugins have not been tested on various WP versions, so it is normal for errors to occur on different WPs. You can directly download the officially recognized version or delete the plugin.

I. File upload issue. When configuring the script, it usually needs to write to the corresponding file. If your file is set as read-only, the consequences can be severe, and you will encounter 500 errors when editing or modifying in the future.

J. Plugin association issue. Some plugins usually require support from other plugins. After deleting one plugin, another plugin may become ineffective. I recommend checking the association when deleting plugins to avoid errors.

  1. I encounter a 500 error when writing logs, pages, or comments.

Usually, there won't be any problems with the logs generated by WP's editor. However, if you prefer to write first and then copy it to the editor, problems may occur.

K. Special character conversion issue. Normally, there won't be any problems with writing regular text. However, if your text contains code or other special characters, such as &, $, <, >, etc., it may cause PHP script parsing errors or database issues when writing to the database. Additionally, for friends who like JavaScript, please be aware that if you don't handle the JS code in your logs, the server may execute it, so be careful. Otherwise, the consequences could be terrifying. I recommend checking for special symbols and script code in your logs before saving them. If you keep encountering errors, you can modify your logs in the database.

  1. I encounter a 500 error when modifying WP themes.

This situation is usually caused by file permission or file protection issues. Additionally, your own modification mistakes could also be a cause.

L. Theme copyright protection issue. If you use a paid theme, your modifications may modify the author's copyright protection files, resulting in abnormal PHP script parsing and a server-side 500 error. I recommend using free themes as much as possible. If you prefer paid themes, you can modify them after obtaining authorization from the author.

M. Modification mistakes. This situation usually results in PHP script parsing errors for your theme. If you modify the main page, header, or footer, you will encounter a 500 error when directly accessing your homepage. However, other WP functions, such as WP-update, will still work. I recommend backing up the theme and modifying the theme files locally after downloading them from the host. If you want a simpler solution, just reinstall the theme.

N. Permission issue again. Usually, after using WP's built-in theme editor to edit theme files, if the modifications fail to save, a 500 error will occur. This situation is generally caused by file rewrite permission issues. I recommend checking the permissions.

  1. After enabling certain WP features (such as email publishing), I encounter a 500 error.

This type of problem is mainly caused by server extension issues. WP requires some server extensions that are not supported, resulting in PHP errors and a server-side 500 error. I recommend contacting the administrator or disabling some features.

  1. WP's own bug. This situation is related to WP's internal issues, and the solution lies within WP itself. You can directly leave a message in the WP community or report it to WP, update to a new version, etc.
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