Icons not uploading with your theme

I am having issues with your Enfold theme, which we just purchase. We develop websites using other WordPress themes and have no issues uploading custom icons and other things. However, we recently purchased your theme for the first time and are not able to upload additional icons through your icon manager.

I tried uploading fontello icon fonts via the IconFont manager. When I try to upload the zip file I am getting the following message:
“Could not add the font because the server didn’t respond. Please try uploading again.” However we host this site and other sites and no other sites are having this issue.

WP and theme are freshly installed and all updated, and I’m not using any plugins. Please let me know the fix to this- thanks!