If you’re using Zsh and oh_my_zsh on macOS or Linux and you’re getting the Zsh zcompinit error, or other errors after the install, it is probably a permissions issue.
A simple fix if you’re on a single-user workstation is with this change to your file permissions.
sudo chmod -R 755 /usr/local/share/zsh \
/usr/local/share/zsh/site-functions