I was able to get around the problem by doing the following, but this is surely an unreasonable expectation from the end user:
sudo dpkg --force overwrite -i /var/cache/apt/archives/libnss3-1d_3.12.0~beta3-0ubuntu1_amd64.deb
I was able to get around the problem by doing the following, but this is surely an unreasonable expectation from the end user:
sudo dpkg --force overwrite -i /var/cache/ apt/archives/ libnss3- 1d_3.12. 0~beta3- 0ubuntu1_ amd64.deb