I think hashcat is not properly installed.

You could use this other method to install
>>> git clone https://github.com/hashcat/hashcat.git

>>> mkdir -p hashcat/deps
>>> git clone https://github.com/KhronosGroup/OpenCL-Headers.git hashcat/deps/OpenCL
>>> cd hashcat/ && make install

>>> ./hashcat — version

>>> ./example0.sh

then try it again.