Uploaded file exceeds the upload_max_filesize directive in php.ini.
You may get the error when you are trying to upload a theme or plugin from your computer .
To solve this error
open .htaccess file in your website directory and paste the below code:-
php_value upload_max_filesize 64M
php_value post_max_size 64M
php_value max_execution_time 300
php_value max_input_time 300