Every experienced you could not upload your favorite WordPress Theme (mine is Divi from ElegantThemes. Get 20% of using this link.)?

Probably there is a upload maximum size of your hosting company.

Quick fix:

Install “WP Htaccess Editor” from “WebFactory Ltd” and edit your .htaccess file

Use the plugin to add this on top

php_value upload_max_filesize 64M
php_value post_max_size 128M
php_value memory_limit 256M
php_value max_execution_time 300
php_value max_input_time 300

just above these lines

# BEGIN WordPress
# The directives (lines) between "BEGIN WordPress" and "END WordPress" are
# dynamically generated, and should only be modified via WordPress filters.
# Any changes to the directives between these markers will be overwritten.

If you get a “500 Internal Server Error”, the host does not allow you to set these global configuration options. Ask to AllowOverride Options.