NPM : checkPermissions Missing write access to /.../node_modules/is

This is a recursive dependency (the is dependency points to node_modules/is, which is also where the is dependency itself will get installed):

"is": "file:node_modules/is"

If you mean to install the is package (this one), remove that line from your package.json and install it properly:

npm i is --save

If you are in a mac or any unix based system try to run the command again as root/Administrator.

sudo npm install