Plugin crashes

I’m trying this plugin in my local site.
Unfortunately this plugin crashes after selecting the time.
Why?
I would use the pro version on a site of a restaurant to make reservations, but I have to set the day for every month of the years.
The pro version allows to select the day and time without being obliged to set up services in the administration site?

Thanks

https://ww.wp.xz.cn/plugins/booking-system/