How do I get X axis mirror pose to work?

Robinson

I want to use the Diffeo simple IK setup, i.e. not Rigify.  Rigify mirror x axis works in pose mode.  The simple IK setup does not.  I renamed all bones to .L and .R, and did the same for the foot IK shape as a test but it still doesn't mirror. 

Is there something else I have to do in Blender?