E1 AIS Appstack calls Null Pointer Exception

I am attempting to use appstack requests on the AIS server to fetch data one page at a time and do actions on multiple forms. I am using the example requests here.

For all of my calls to the appstack resource, I'm getting a Java NullPointerException. Is there a configuration issue with appstack? Or is this an issue with the request?

Using SoapUI to POST the following to <ais_endpoint>/jderest/v2/appstack

{

  "token" : "044taYmXulJDu4b0/9PuYG3HQYCv03W5vqcGjEMzBW6O1k=MDE5MDEyODMwOTA4MjIxMDI1NjgyNTg4NDEwLjEzMi4zLjIxMTE1MDY2NDc0NDQwOTI=",

  "ssoEnabled" : false,

  "aliasNaming" : true,

  "showActionControls" : false,

  "includeTimings" : false,

  "allowCache" : true,