Installation delivers white page

The plugin sounds perfect but for unknown reasons I am not able to install it.
I have tried different wordpress versions, different templates and diffent hosts.

With one I got this error message:

Warning: require_once(/www/htdocs/xxx/xxx/wp-content/plugins/book-a-room/bookaroom-meetings-locale.php): failed to open stream: No such file or directory in /www/htdocs/xxx/xxx/wp-content/plugins/book-a-room/bookaroom.php on line 613

Fatal error: require_once(): Failed opening required '/www/htdocs/xxx/xxx/wp-content/plugins/book-a-room/bookaroom-meetings-locale.php' (include_path='.:/usr/share/php:..') in /www/htdocs/xxx/xxx/wp-content/plugins/book-a-room/bookaroom.php on line 613

Do you have an idea, what I am doing wrong?

Thanks for your help.

https://www.ads-software.com/plugins/book-a-room/