Troubleshooting the 404 Errors in WordPress
The 404 or Not Found error message is a HTTP standard response code indicating that your browser was able to communicate with your website but the server could not find what was requested. We will look into the possible causes and solutions in this documentation.
Deleted Page or Post
A link pointing to a deleted post or page, as well as Google indexing a deleted post or page will cause 404 not found for your visitors. You will have to make sure your links in your content are updated.
mod_rewrite is not enabled
In WordPress admin - Settings - Permalinks. You have just selected a permalink structure for your site (not default setting). After clearing your browser cache and visiting your website. You found that all your menu or post links leads to 404 not found.
In this case, your server may not have mod_rewrite enabled. mod_rewrite is an Apache Server extension that allows for rewriting url. You will have to check with your web hosting company to verify this issue.
Missing .htaccess file
WordPress may be unable to create the required .htaccess file due to file and folder permission. You will need to manually create a .htaccess file. You should ask your web hosting company to assist in creating your .htaccess file. A wrongly configured .htaccess file can create more issues.
It's also possible for you, to have accidentally deleted your .htaccess file. In this case, you will need to login to WordPress admin - Settings - Permalinks and re-select your permalink structure and click on Save Changes button. Clear your browser cache and re-visit your website.
Custom Post Type 404 Errors
You may have a plugin that uses custom post types. In this case, make sure your post title and post slug does not contain any word that is similar to the custom post type name or slug. It can cause confusion to WordPress when it tries to retrieve the post or page from database, this can result in 404 not found.
For your information, our products at Press Customizr does not use custom post types.
Wrong Permalink Structure
You may have set a wrong custom permalink structure. You have to use structure tags that are recognize by WordPress. You can refer to Using Permalinks for the list of structure tags available.