Plugin installation error

I’m trying to install the plugin on my server, but is accusing the error

PHP Warning: require_once(inc/class-seed-csp4.php) [function.require-once]: failed to open stream: No such file or directory in E:\home\viverdis\viverdis.com.br\web\wp-content\plugins\coming-soon\coming-soon.php on line 62
PHP Fatal error: require_once() [function.require]: Failed opening required ‘inc/class-seed-csp4.php’ (include_path=’.;C:\php\pear’) in E:\home\viverdis\viverdis.com.br\web\wp-content\plugins\coming-soon\coming-soon.php on line 62

The requested file is on the server and still gives error

https://ww.wp.xz.cn/plugins/coming-soon/