How to install new nodes.is there a wrong installation of node red in Openplotter

[tocan]

I allways have a problem to install something in nodered like new nodes. Where is my mistake?

npm install node-red-node-mysql

any solution or tip how to do?

pi@openplotter:~ $ cd .node-red/
pi@openplotter:~/.node-red $ sudo npm install node-red-node-mysql
npm ERR! Linux 4.9.35-v7+
npm ERR! argv "/usr/bin/nodejs" "/usr/bin/npm" "install" "node-red-node-mysql"
npm ERR! node v6.11.2
npm ERR! npm  v3.10.10
npm ERR! path /home/pi/.node-red/node_modules/node-red-contrib-freeboard
npm ERR! code EISGIT

npm ERR! git /home/pi/.node-red/node_modules/node-red-contrib-freeboard: Appears to be a git repo or submodule.
npm ERR! git     /home/pi/.node-red/node_modules/node-red-contrib-freeboard
npm ERR! git Refusing to remove it. Update manually,
npm ERR! git or move it out of the way first.

npm ERR! Please include the following file with any support request:
npm ERR!     /home/pi/.node-red/npm-debug.log
pi@openplotter:~/.node-red $