Here are the most common reasons that affect the import process:
Files and folders permission: All files in “wp-content” directory should have CHMOD 644 and all folders in “wp-content” directory should have CHMOD 755.
Memory limit: Make sure your website have enough memory limit. To increase memory limit, you should go to root directory of WordPress and open “wp-config.php”. Then find the line that has “WP_DEBUG” and add “define(‘WP_MEMORY_LIMIT’, ’64M’);” after that line.
Theme location: Please make sure “massive-dynamic” theme folder is located directly in “wp-content > themes”. If you rename the theme folder or move it into another folder, theme settings will not import correctly.