The request and response files are properly formatted and we are still facing a Null Pointer Exception when trying to create a virtual service image from RR pairs.
This issue was found with LISA 7.5.2.
If, for some reason, if you faced a legitimate NPE while creating a service image from request and response pairs, you will need to restart the LISA Workstation for it to work fine again.
This issue is fixed with the supported releases of DevTest.
CA LISA 7.5.2 is out of support since June 2016 - DevTest Solutions Release and Support Lifecycle Dates