Hello Siddharth,
I believe the problem is not the request and response files. I could create a Virtual Service with the two files you provided using the Portal. No issues.
If removing the VSE_2013 under $DEVTEST_HOME/vseRecording did not help, please could you provide what is the DPH you are using and if you are modifying anything with the request or response during the SI creation.
Additionally, which browser you are using?
Thank you,
Heloisa