The "HTTP Error" during media upload in WordPress is a relatively common issue. It can be caused by a variety of factors. Here are steps you can take to troubleshoot and potentially resolve this issue:

1. Check File Size and Type:

   • Make sure the file you're trying to upload meets the maximum file size and type requirements set by your server. You can check and adjust these settings in your server's PHP configuration (php.ini).

2. Increase PHP Memory Limit:

   • Sometimes, low PHP memory limits can cause HTTP errors during uploads. You can try increasing the memory limit by adding the following line to your wp-config.php file:
   SQL

2. define('WP_MEMORY_LIMIT', '256M');

   You can increase the value as needed.

3. Check Server Disk Space:

   • Ensure that there is enough available disk space on your server to accommodate the file you're trying to upload.

4. Check File Permissions:

   • Verify that the directories where WordPress stores uploads have the correct permissions. Folders  wp-content/uploads should typically have permissions set to 755 and files to 644.

5. Temporarily Disable Plugins and Themes:

   • Deactivate all plugins and switch to a default theme like Twenty Twenty-One. Then, try uploading media again. If it works, reactivate your plugins and themes one by one to identify the problematic ones.

6. Check for ModSecurity Rules:

   • Some hosting providers use ModSecurity rules that might block certain types of file uploads. Contact your hosting provider to see if this is the case.

7. Check .htaccess File:

   • Check your .htaccess file for any rules that might be causing conflicts. You can temporarily rename it to something like .htaccess_old this and try uploading again.

8. Disable Flash in Media Uploader:

   • Go to your media uploader (Add New Media) and click on the "Browser Uploader" link. This will use the older uploader that doesn't rely on Flash.

9. Use a Different Browser:

   • Sometimes, browser-specific issues can cause upload problems. Try using a different browser to see if it resolves the issue.

10. Check for Firewall or Security Plugin Interference:

    • If you're using a security plugin or firewall on your site, it might be blocking certain file uploads. Temporarily disable them and try uploading again.

11. Check PHP Version:

    • Ensure you're using a supported version of PHP. Outdated versions might have compatibility issues.

12. Check for Special Characters in File Names:

    • Sometimes, special characters or spaces in file names can cause issues during uploads. Try renaming the file and uploading it again.

13. Contact Your Hosting Provider:

    • If none of the above solutions work, contact your hosting provider. They might be able to provide specific guidance or make adjustments on the server side.

Remember to always back up your website before making significant changes. If the issue persists, consider seeking help from a developer or the WordPress support forum, where you can provide more specific details about your situation.