Gulp Error: File not found with singular glob:

I am getting the following error runing Gulp. 

c:\>gulp

[10:57:02] Using gulpfile C:\gulp_project\gulpfile.js

[10:57:02] Starting 'default'...

[10:57:02] Starting 'js'...

[10:57:02] 'js' errored after 20 ms

[10:57:02] Error: File not found with singular glob: C:/node_modules/tether/dist/js/tether.min.js (if this was purposeful, use `allowEmpty` option)

at Glob.<anonymous> (C:\gulp_project\node_modules\glob-stream\readable.js:84:17)

at Object.onceWrapper (events.js:286:20)

at Glob.emit (events.js:198:13)

at Glob.EventEmitter.emit (domain.js:448:20)

at Glob._finish (C:\gulp_project\node_modules\glob\glob.js:197:8)

at done (C:\gulp_project\node_modules\glob\glob.js:182:14)

at Glob._processSimple2 (C:\gulp_project\node_modules\glob\glob.js:688:12)

at C:\gulp_project\node_modules\glob\glob.js:676:10

at Glob._stat2 (C:\gulp_project\node_modules\glob\glob.js:772:12)

at lstatcb_ (C:\gulp_project\node_modules\glob\glob.js:764:12)

[10:57:02] 'default' errored after 26 ms

Any ideas? Please help :(