Build fails with missing 'meteor/tools'

i am getting a strange error -
Meteor version 1.6.0.1 with react

everything builds ok but when opening in browser i get this error -

Uncaught Error: Cannot find module 'meteor/tools'
    at makeMissingError (modules-runtime.js?hash=5e485d3e2a49d2506f7ca0df72fcd6a3216a83a5:241)
    at require (modules-runtime.js?hash=5e485d3e2a49d2506f7ca0df72fcd6a3216a83a5:251)
    at index.jsx (index.jsx:1)
    at fileEvaluate (modules-runtime.js?hash=5e485d3e2a49d2506f7ca0df72fcd6a3216a83a5:353)
    at require (modules-runtime.js?hash=5e485d3e2a49d2506f7ca0df72fcd6a3216a83a5:248)
    at app.js?hash=054b06605887f54b7538a14930dc4972ccce3d12:1072
makeMissingError @ modules-runtime.js?hash=5e485d3e2a49d2506f7ca0df72fcd6a3216a83a5:241
require @ modules-runtime.js?hash=5e485d3e2a49d2506f7ca0df72fcd6a3216a83a5:251
index.jsx @ index.jsx:1
fileEvaluate @ modules-runtime.js?hash=5e485d3e2a49d2506f7ca0df72fcd6a3216a83a5:353
require @ modules-runtime.js?hash=5e485d3e2a49d2506f7ca0df72fcd6a3216a83a5:248
(anonymous) @ app.js?hash=054b06605887f54b7538a14930dc4972ccce3d12:1072

this starts abruptly, i mean i have to changed anything it just pops this message

i have to create a new project to erase this message?
any suggestions?