When you first set up your account or an account for a client you may come across an error when trying to upload a file on cPanel using File Manager.
The error message you receive can vary between web browsers.
To fix this is issue you simply need to increase the upload_max_filesize on cPanel. This can be done in one of two ways depending on your server configuration.
You should now be able to upload your files on cPanel without any error messages.