nvm is not compatible with the npm config "prefix" option: currently set to "/home/user/.npm-global"
Run `nvm use --delete-prefix v6.9.2` to unset it.
user@ubuntu:~$ nvm use --delete-prefix v6.9.2 --silent
user@ubuntu:~$ node --version
v6.9.2
user@ubuntu:~$ npm --version
3.10.9
rm -rf ~/.nvm
rm -rf ~/.npm
rm -rf ~/.bower
and remove line source ~/.nvm from yours .bashrc or .zshrc Source: nvm-sh/nvm#298