When you are mapping clipboard page using JSON mapping in Pega REST connector rules, you might have encountered issues when the value of some fields has got special characters such as back slash or double quotes etc.

You can resolve the issues by updating or creating a dynamic system setting with below details.

Purpose : json/escapeSpecialCharacters 
Owning Ruleset : Pega-IntSvcs 
Value : true

This will cause Pega to add escape characters to the generated JSON so the service provider will receive valid JSON input in the request.