calpress wiped ont my yearly calendar

Calpress free ro calpress pro will not set up. After clicking on site setup snd going to new page, I recieve this site error.

The website cannot display the page

HTTP 500

Most likely causes:
?The website is under maintenance.
?The website has a programming error.

I started getting this error after i clicked on add on to check programs and went back to new page to find all my work gone. From that point forward all I get is this same error

https://www.ads-software.com/plugins/calpress-event-calendar/