I've install Jenkins 1.602 on Mac OS X 10.10.
When I install the gradle plugin and go into the Configure System page under Gradle I have Gradle Installations and I add Install from Gradle.org installer - the problem is I'm getting textbox instead of ComboBox to enter the Version parameter.

I've try to write 2.2.1 inside the Version textbox but then I got this output when building the job:

[Gradle] - Launching build.
Invalid tool ID 2.2.1
[Gradle] - [ERROR] Can't retrieve the Gradle executable.