_From @KirsiYin on December 23, 2016 3:26_
Ionic version: (check one with "x")
[ ] 1.x
[x] 2.x
I'm submitting a ... (check one with "x")
[x] bug report
[ ] feature request
[ ] support request => Please do not submit support requests here, use one of these channels: https://forum.ionicframework.com/ or http://ionicworldwide.herokuapp.com/
this is my info
Your system information:
ordova CLI: 6.4.0
Ionic Framework Version: 2.0.0-rc.4
Ionic CLI Version: 2.1.18
Ionic App Lib Version: 2.1.9
Ionic App Scripts Version: 0.0.48
ios-deploy version: Not installed
ios-sim version: Not installed
OS: Windows 10
Node Version: v6.9.2
Xcode version: Not installed
after run ionic serve, it shown error like that
ionic-conference-app@ ionic:serve C:\Users\Hoang Xuan Thanh\Downloads\ionic\ionic-conference-app-master\ionic-conference-app-master
ionic-app-scripts serve "--v2" "--address" "0.0.0.0" "--port" "8100" "--livereload-port" "35729"keywords if/then/else require v5 option
module.js:471
throw err;
^Error: Cannot find module 'reflect-metadata'
at Function.Module._resolveFilename (module.js:469:15)
at Function.Module._load (module.js:417:25)
at Module.require (module.js:497:17)
at require (internal/module.js:20:19)
at Object.(C:\Users\Hoang Xuan Thanh\Downloads\ionic\ionic-conference-app-master\ionic-conference-app-master\node_modules\@ionic\app-scripts\dist\aot\aot-compiler.js:4:1)
at Module._compile (module.js:570:32)
at Object.Module._extensions..js (module.js:579:10)
at Module.load (module.js:487:32)
at tryModuleLoad (module.js:446:12)
at Function.Module._load (module.js:438:3)npm ERR! Windows_NT 10.0.14393
npm ERR! argv "C:\Program Files (x86)\nodejs\node.exe" "C:\Users\Hoang Xuan Thanh\AppData\Roaming\npm\node_modules\npm\bin\npm-cli.js" "run" "ionic:serve" "--" "--v2" "--address" "0.0.0.0" "--port" "8100" "--livereload-port" "35729"
npm ERR! node v6.9.2
npm ERR! npm v4.0.5
npm ERR! code ELIFECYCLE
npm ERR! ionic-conference-app@ ionic:serve:ionic-app-scripts serve "--v2" "--address" "0.0.0.0" "--port" "8100" "--livereload-port" "35729"
npm ERR! Exit status 1
npm ERR!
npm ERR! Failed at the ionic-conference-app@ ionic:serve script 'ionic-app-scripts serve "--v2" "--address" "0.0.0.0" "--port" "8100" "--livereload-port" "35729"'.
npm ERR! Make sure you have the latest version of node.js and npm installed.
npm ERR! If you do, this is most likely a problem with the ionic-conference-app package,
npm ERR! not with npm itself.
npm ERR! Tell the author that this fails on your system:
npm ERR! ionic-app-scripts serve "--v2" "--address" "0.0.0.0" "--port" "8100" "--livereload-port" "35729"
npm ERR! You can get information on how to open an issue for this project with:
npm ERR! npm bugs ionic-conference-app
npm ERR! Or if that isn't available, you can get their info via:
npm ERR! npm owner ls ionic-conference-app
npm ERR! There is likely additional logging output above.npm ERR! Please include the following file with any support request:
npm ERR! C:\Users\Hoang Xuan Thanh\Downloads\ionic\ionic-conference-app-master\ionic-conference-app-master\npm-debug.log
There was an error serving your Ionic application: There was an error with the spawned command: serve
_Copied from original issue: driftyco/ionic#9770_
_From @graphefruit on December 23, 2016 11:35_
@KirsiYin Have you tried to install a starter app, is it working there?
-> ionic start myProject --v2
Hello guys am having exactly the same problem,whats the solution please.
Same problem here - even all the way up to node 7.4.0 now as well. Also completely reinstalled ionic to boot.
ionic serve doesnt work
Cordova CLI: 6.5.0
Ionic Framework Version: 2.0.0
Ionic CLI Version: 2.2.1
Ionic App Lib Version: 2.2.0
Ionic App Scripts Version: 1.0.0
ios-deploy version: Not installed
ios-sim version: Not installed
OS: Windows 10
Node Version: v6.9.4
Xcode version: Not installed
Module.js:471
throw err;
^
Error: Cannot find module 'reflect-metadata'
at Function.Module._resolveFilename (module.js:469:15)
at Function.Module._load (module.js:417:25)
at Module.require (module.js:497:17)
at require (internal/module.js:20:19)
at Object.
at Module._compile (module.js:570:32)
at Object.Module._extensions..js (module.js:579:10)
at Module.load (module.js:487:32)
at tryModuleLoad (module.js:446:12)
at Function.Module._load (module.js:438:3)
if you remove node_modules folder and install again ionic with g "npm install -g ionic cordova"
Same problem, any solution to this?
Found a fix for it:

--> ionic is no longer adding reflect-metadata to the package.json
i find this solution it works:
in the Ionic Project, open:
package.json
Add this in it:
"reflect-metadata": "^0.1.3",
Then run this on console: npm install
and Then run this: 'npm rebuild or 'npm rebuild node-sass''
Ready to run ionic serve to see your app ;)
For Info
I had this problem but only by installing new apps package from ionic's github (whatever the template).
For another reason i've updated node for Node Version: v6.10.2.
Since I don't have anymore this pb.