Hi,
I got the solution by myself.
You need to re-add that certificate to your machine or chose another certificate.
To choose another certificate or to recreate one, head over to the Project's properties page, click on Signing tab and either
Click on Select from store
Click on Select from file
Click on Create test certificate
Once either of these is done, you should be able to build it again.
This is the solution for the error.
Thanks.