Apple - OS X 10.11 unable to press "allow" on Keychain Access dialogs

I encountered this same issue today. I could not "Allow" or "Always Allow" any programs, nor could I confirm my password in any dialogues. The interface wouldn't shake, even if I had entered the incorrect password.

I use Synergy to facilitate programming over several different computers. My mouse and keyboard do not belong to the Mac OSX device. I was able to hit the "Allow" button once I used a mouse actually hooked up the Mac OSX device.

In general, try turning off any virtual or physical KVM services and use the Mac mouse/keyboard directly.

Hopefully this can help you or someone else who comes here looking for help.

For me, I had to go to System Preferences -> Security & Privacy -> Privacy.

On the left, click on Accessibility, then on the right side uncheck every checkbox. This resolves the problem. For me, I had Steam (from VALVe) running and Karabiner (keyboard key editor) which also was allowed to control the computer.

Just got this fixed. I use a plugin called SmoothMouse that improves acceleration of trackpad and mouse. It likely integrates with the accessibility APIs in OS X and thus triggers the same behavior as screensharing. Disabling the plugin resolved the problem.

You can see the sister StackOverflow question here as well.