I have to record a large test plan including 4 transactional controllers and response assertions for the UI side but at the time of login there is token generated and I am doing correlation manually. I have used the regular expression extractor to extract the token from my login response but it gives the following error: org.apache.oro.text.MalformedCachePatternException: Invalid expression: (?<=("|')token("|'):("|'))(.*?)("|')(=?) Sequence (?<...) not recognized. Please guide me also how can I pass this TOKEN on the further request as each request has its own header manager. How I can pass THIS TOKEN OVER 4 TRANSACTIONAL CONTROLLER. I am adding my test plan for reference. Please guide me on a suitable process to do this.