@TanyaS58 RootNode becomes null because you are trying to run Apply Parse XML on a value that is basically JSON text, not a real XML structure with child elements (wrapping JSON inside <Response>...</Response> still leaves only plain text, so Pega cannot build a page tree). The fix is: first run Apply Parse XML only on the actual API XML response (the one that contains tags like <raw> / <derived>), and extract the derived_data/raw string from the parsed page. Then “clean” that string by removing <![CDATA[, ]]>, and any XML-escaped characters like ", <, > if they exist. After that, run Apply Parse JSON / pxDeserializeJSON on the cleaned JSON string (and map the results from the parsed JSON page, not from the raw text). Also double-check your substring logic: if you use indexOf("</raw>"), make sure you are not cutting off the last } or leaving extra characters before {, because either one will throw “invalid JSON” even if the original payload is valid.