simple booking calendar

Roland,
I purchased two wp simple calendars … one for each of the two web sites. One site the calendar works great. However the second site the calendar will not work. Can not save the date changes in the widget at all. When I click the “save change” button the changes revert back to original defaults and the short codes do not show.

https://www.ads-software.com/plugins/wp-simple-booking-calendar/