Hi adNaveed,
After install ALM 12, did you register component from ALM 12? Did you uninstall the old version of excel add-in and install the new one for ALM 12?
Could you please check with the steps below:
1- Uninstall ALM client by using uninstall utility client (please check the full clean up option):
http://support.openview.hp.com/selfsolve/document/KM1400068
2- Uninstall excel add-in.
3- Log in your machine with full admin rights, open IE and enter ALM 12 url then register component again.
4- Download excel add-in for ALM 12 via https://hpln.hp.com/page/alm-excel-addin-page then install it
5- Check your issue again
Thank you and regards,