So it is fixed now? if not try this, off course some are Linux commands only, you need to change rm -rf for your OS equivalent, this will clean your pc of ionic, clean npm's cache and reinstall:
npm uninstall -g ionic && npm uninstall -g cordova && rm -rf node_modules && npm cache clear && npm cache clean && npm i -g cordova ionic@beta && npm i && ionic serve -s -c