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kotlinlang

If you read the error message from Jackson, it tells you the problem, `Parameter specified as non-null is null` which says that something is missing in the JSON and when trying to put the NULL value into a parameter it cannot, the parameter of `method us.kalmyk.webservices.external.RunePages$RunePage.&lt;init&gt;` (which is the constructor of `RunePage`) and it tells you the parameter name `parameter slots` ... so all the information is there to figure out the error.