We were looking online for a guide to fixing this error within the WordPress media gallery when uploading a .mp3 file and found no support for the issue. After finding a solution we decided to put together a simple guide to help you out in 5 easy steps.
Step 1. Login to your Cpanel. You can typically gain access by searching – yourdomainname.com/cpanel. If you do not know the credentials, log in to your hosting account, and navigate to your Cpanel.
Step 2. Once you are in the Cpanel open your ‘file manager’.
*Important – ensure you have ‘show hidden files’ selected – You may need to click ‘settings’ (top right corner of file manager) and select this option.

Step 3. Click search and type ‘php.ini’ -> Right-click this file and choose edit.
*If you can’t find the PHP.ini, navigate to your root folder (usually public_html) and click ‘create new file’ in the top left corner. Name it PHP.ini then right-click the file and select edit.
Step 4. Within the php.ini file change the following values:
memory_limit = 256M
post_max_size = 76M
upload_max_filesize = 64M
*You may need to adjust the values to higher numbers for larger files.

Step 5. Save the PHP.ini file.
Step 6. Navigate back to WordPress and refresh your media gallery, and now upload your media file.
*Please Note – In rare instances, you may need to also search for your user.ini file and repeat the steps above that you did with the php.ini file.
If you are trying to operate on below-standard hosting, we strongly suggest taking a look at hosting your website.