How can I uninstall a device admin if the Deactivate button doesn't work?

I am trying to uninstall CM Security. It's a device admin, so I go to Settings, Security, then Device Administrators, and try to uncheck the box next to CM Security, then a screen comes up listing the privileges the app has. The options are Cancel and Deactivate. When I click Deactivate, the button depresses, but it does nothing. I can click it as much as I want, and nothing happens. How can I deactivate a device admin when this problem occurs?