Nested error: Cannot find module 'typescript'[solved]

I am acting tutorial 1 & 2, local install & your first app

Found following issues:

victor-macbookair2:dojo victorhu$ cd first-dojo-app/

victor-macbookair2:first-dojo-app victorhu$ dojo build --mode dev --watch --serve

Commands are not available: Error: Failed to load module /usr/local/lib/node_modules/@dojo/cli-build-app

Nested error: Cannot find module ‘typescript’

What should I do? I tried uninstall and re-install @dojo/cli & @dojo/cli-create-app, but it did not work.

It seems solved , after I manually deleted @dojo folder under /usr/local/lib/node_modules/, and reinstalled again.