Calex - The Calendar Exporter 4+

But everytime I try to open it:

Calex quit unexpectedly.

Click Reopen to open the application again. Click Report to see more detailed information and send a report to Apple.

I frequently need to send people my availability (I have an online scheduling system, but sometimes it doesn’t feel appropriate to send that to someone you are asking to meet with). This great little program generates a text list of what times in my calendar(s) are free. You first select what calendars you want it to take into account, and the time period over which you want it to find free time, and then it generates something you can send in an email or message. It’s lately giving some error messages on closure (perhaps since El Capitan or a bit earlier) but still usable. Would be great if the bug was addressed.

Just bought it and all I get is "Calex quit unexpectedly error" - maybe this worked at one time but currently apears to be unsupported and completely unusable.