Divvy application not opening or showing any error message
It's a known problem since 11/10. Update only needs to be approved by Apple. Should be available tomorrow. In the meantime you can use the demo version of the website.

https://twitter.com/MizageApps/status/664712553323335680

In the meantime, the developer recommends that you use the trail version.

https://twitter.com/MizageApps/status/664820916791054336