Sometimes lisa.vse.response has properties which were not evaluated and causes an issue at application end.
For example, creating a custom data protocol and transient response is an xml that has some expressions in it like this: {{=dataValue}}.When trying to update this xml but the expressions are not evaluated at the time of the response update and get an error.

How to evaluate properties in lisa.vse.response which is in Transient form.

All DevTest supported versions.

Using testExec.parseInState on the VSE response should resolve the issue.

https://communities.ca.com/message/242055518-re-how-to-evaluate-expressions-in-transient-response-before-it-goes-to-custom-data-handler?commentID=242055518&et=watches.email.thread#comment-242055518