Once you’ve renamed the .htaccess file, try visiting their website to see if that caused a problem. If so, then congratulations, you have now fixed the internal server error.
Before proceeding with other things, make sure you go to the Settings – Permalinks page in the WordPress admin panel and click the Save button without making any changes. This will create a new .htaccess file for you with correct rewrite rules to ensure your post pages don’t return a 404 error.
If the search for the corrupted .htaccess file didn’t work for you, then you need to continue reading this article.
Increase PHP memory limit.
Sometimes internal server errors can occur if you hit your PHP memory limit.
If you only see the internal server error when trying to login to your WordPress admin or upload an image in your wp-admin, then you should increase the storage limit by following these steps:
- Create an empty text file called php.ini
- Paste this code in: memory=64MB
- Save the file.
- Upload it to your /wp-admin/ folder via FTP.
Several users have said that the admin page issue above has been fixed for them.
If increasing the memory limit fixed the problem for you, then you only fixed the problem temporarily. You still have to find the cause that is exhausting your memory limit.
This can be a poorly coded plugin or even a theme feature. I highly recommend that you offer your WordPress web hosting company to look at the server logs to find the exact diagnosis.
Disable all plugins.
If none of the above solutions worked for you, then this error is due to a specific plugin. It’s also possible that it’s a combination of plugins that don’t work well together.
Unfortunately, there is no easy way to find out. You must disable all WordPress plugins at once. You can do that via the FTP server. To do this, go to wp-content > Plugins and rename the plugin folder to e.g. Plugins_disabled.
If you should reach the backend again, you can rename the folder to Plugins.
If disabling all plugins fixed the error, then you know it’s one of the plugins that caused the error. Get rid of this plugin and report the bug to the plugin developer.
Re-upload core files.
If the plugin option didn’t fix the internal server error, it’s worth reloading the wp-admin and wp-includes folder from a fresh WordPress install.
This won’t remove any of your information, but it may solve the problem in case a file got corrupted.
First, you need to visit the WordPress.org website and click the Download button.
This will install the WordPress zip file onto your computer. You need to unzip the zip file and inside is a WordPress directory.
Next, you need to connect to your WordPress website using an FTP client. Once connected, go to the root folder of their website. It’s the folder that contains the wp-admin, wp-includes, and wp-content folders.
In the left column, open the WordPress folder on your computer. Now you need to select wp-includes and wp-admin folders and then right click and choose “Upload”.
Your FTP client will now transfer this folder to your server. You will be asked if you want to overwrite the data. Select “Overwrite” and then “Always use this action”.
Your FTP client will now replace your older WordPress files with newer copies. If your WordPress files got corrupted then this step will fix the internal server error for you.
Ask your provider.
If all methods fail to fix internal server errors on your website, then it’s time to get more help. Contact your web hosting support team who can review the server logs and determine the cause of the error.
Hope the bug is fixed now.