This is one problem you face when you try to upgrade your WordPress blog / any plugin associated with WordPress that is self hosted on HostGator servers.
I’ve noticed this problem when I try to update the blog which has customized / commercial theme installed. I decided to change the theme to a simple theme provided by WordPress by default and tried updating the blogs and / or plugins and it worked fine.
- Switch the theme from ‘whatever’ current to basic one (I switched to ‘Twenty Fifteen’)
- Updated WordPress to latest version and updated the plugins.
- Reverted to custom theme.
This should help.