Here is the issue. This error FIRST occurred pointing to this
ImportError: /lib/x86_64-linux-gnu/libc.so.6: version `GLIBCXX_3.4.19' not found (required by /home/avijit/anaconda2/envs/tensorflow/lib/python2.7/site-packages/tensorflow/python/_pywrap_tensorflow.so)
that I solved using this glibcxx-3-4-20-not-found-how-to-fix-this-error
BUT, now it has another similar problem
ImportError: /lib/x86_64-linux-gnu/libc.so.6: version `GLIBC_2.16' not found (required by /home/avijit/anaconda2/envs/tensorflow/lib/python2.7/site-packages/tensorflow/python/_pywrap_tensorflow.so)
How to solve these issues? Why do they keep coming one after another?