applyEdits add JSON string to a feature as an attachment

[aaronmontgomery]

I am trying to add a JSON string as an attachment to a feature using applyEdits, and I am receiving a 500 error Unable to perform applyEdits operation.  I have attached the code I am running against a test FeatureServer.  Will someone please explain why the code doesn't work.

Thank You,

Aaron Montgomery