Install libnetfilter-cthelper0-dev by entering the following commands in the terminal:
sudo apt update sudo apt install libnetfilter-cthelper0-dev
Development files for libnetfilter-cthelper0
libnetfilter_cthelper is the userspace library that provides the programming interface to the user-space helper infrastructure available since Linux kernel 3.6. With this library, you register, configure, enable and disable user-space helpers. . This package provides development files and static libraries.