JSONPath

Unknown JSONPath function  

Reports an unknown name in a JSONPath function call instead of known standard function names: concat, keys, length, min, max, avg, stddev, sum.

Unknown JSONPath operator  

Reports an unknown operator on a JSONPath expression instead of one of the standard ones: in, nin, subsetof, anyof, noneof, size, empty, contains.

Unknown property key used for JSONPath evaluate expression  

Reports a key in a JSONPath expression that is missing in the source JSON document to evaluate.