I got "ImportError of libcudnn.so.6" after Ubuntu apt update although I have no idea how apt update causes the error. The solution is re-install cuDNN.
Library files of cuDNN disappeared from a directory where is one of LD_LIBRARY_PATH. So, I just followed a guidance here.
- download cuDNN version 6.0
- copy the header and lib files as sudo cp include/cudnn.h /usr/local/cuda-8.0/include sudo cp lib64/lib* /usr/local/cuda-8.0/lib64/
- make symbolic links sudo chmod +r libcudnn.so.6.0.21 sudo ln -sf libcudnn.so.6.0.21 libcudnn.so.6 sudo ln -sf libcudnn.so.6 libcudnn.so sudo ldconfig
