I ran into this problem using WordPress today where I reached the max upload size on my client's Godaddy server on a shared hosting account. If you get this error in WordPress, while uploading a file, by the way, it's probably a max file size issue:
That's all it said! So it took me a few guesses to figure out what that "Error: 1" message meant.
How to increase the Max File Size Setting in Cpanel
1 - go to your site's Cpanel by going to yoursite.com/cpanel and log in with the user and password your hosting provider provides for you. You should see this when logged in:
2) scroll down until you see the "Select PHP Version" link in Cpanel that is circled in the below image and click on it:
3) That will take you to the PHP version selection page. Then click the link in the upper right corner of the page that you see circled in the below image:
4) Clicking the "Switch to PHP Options" link in the above image will take you to a PHP settings page. Look for the upload_max_filesize setting that you see circled in the image below and set it to something higher than 2M according to your individual needs:
5) After you change it from "2M" to something higher as needed, click the "Apply" button directly to the right of the dropdown and then be sure to also click the "Save" button near the bottom-left of the page as well and then you are done!