NIS not opening after being prompted to restart computer using MAC

I restarted my mac after being prompted to do so from Norton.  When rebooted the Norton symbol was not showing in top bar.  When I went to Finder to open, it quickly appeared in dock and then was gone.  So I rebooted again.  The Norton symbol is now showing in upper right top bar, however, when I click on that to open NIS, it quickly appears in dock and then is gone again.  I can't access NIS at all.  

I have had more issues with NIS than ever before and not at all sure I will continue with this product.  It has cost me at least 15 hours of work with the many issues I have had.  

Appreciate any advice on how to resolve.  Hoping I don't get met with you must uninstall and reinstall which seems to be the answer to all of my issues.

Thanks,

Dawson