Angular2 QuickStart npm start is not working on it’s next day

I have tried Angular2 QuickStart. To execute this I have used npm start. On it’s first try it is working fine. But on it’s next day when I try to run using npm start it throws an error like this:

0 info it worked if it ends with ok
1 verbose cli [ 'C:\Program Files\nodejs\node.exe',
1 verbose cli   'C:\Program Files\nodejs\node_modules\npm\bin\npm-cli.js',
1 verbose cli   'start' ]
2 info using [email protected]
3 info using [email protected]
4 verbose run-script [ 'prestart', 'start', 'poststart' ]
5 info lifecycle [email protected]~prestart: [email protected]
6 verbose lifecycle [email protected]~prestart: unsafe-perm in lifecycle true
7 verbose lifecycle [email protected]~prestart: PATH: C:Program Filesnodejsnode_modulesnpmbinnode-gyp-bin;C:wamp64wwwprakash_angular3node_modules.bin;C:ProgramDataOracleJavajavapath;C:Windowssystem32;C:Windows;C:WindowsSystem32Wbem;C:WindowsSystem32WindowsPowerShellv1.0;C:Program Files (x86)SkypePhone;C:wamp64binphpphp5.6.25;C:ProgramDataComposerSetupbin;C:Program Filesnodejs;C:Usersvis-2113AppDataRoamingnpm
8 verbose lifecycle [email protected]~prestart: CWD: C:wamp64wwwprakash_angular3
9 silly lifecycle [email protected]~prestart: Args: [ '/d /s /c', 'npm run build' ]
10 silly lifecycle [email protected]~prestart: Returned: code: 1  signal: null
11 info lifecycle [email protected]~prestart: Failed to exec prestart script
12 verbose stack Error: [email protected] prestart: `npm run build`
12 verbose stack Exit status 1
12 verbose stack     at EventEmitter.<anonymous> (C:Program Filesnodejsnode_modulesnpmlibutilslifecycle.js:255:16)
12 verbose stack     at emitTwo (events.js:106:13)
12 verbose stack     at EventEmitter.emit (events.js:191:7)
12 verbose stack     at ChildProcess.<anonymous> (C:Program Filesnodejsnode_modulesnpmlibutilsspawn.js:40:14)
12 verbose stack     at emitTwo (events.js:106:13)
12 verbose stack     at ChildProcess.emit (events.js:191:7)
12 verbose stack     at maybeClose (internal/child_process.js:920:16)
12 verbose stack     at Process.ChildProcess._handle.onexit (internal/child_process.js:230:5)
13 verbose pkgid [email protected]
14 verbose cwd C:wamp64wwwprakash_angular3
15 error Windows_NT 6.1.7601
16 error argv "C:\Program Files\nodejs\node.exe" "C:\Program Files\nodejs\node_modules\npm\bin\npm-cli.js" "start"
17 error node v6.11.4
18 error npm  v3.10.10
19 error code ELIFECYCLE
20 error [email protected] prestart: `npm run build`
20 error Exit status 1
21 error Failed at the [email protected] prestart script 'npm run build'.
21 error Make sure you have the latest version of node.js and npm installed.
21 error If you do, this is most likely a problem with the angular-quickstart package,
21 error not with npm itself.
21 error Tell the author that this fails on your system:
21 error     npm run build
21 error You can get information on how to open an issue for this project with:
21 error     npm bugs angular-quickstart
21 error Or if that isn't available, you can get their info via:
21 error     npm owner ls angular-quickstart
21 error There is likely additional logging output above.
22 verbose exit [ 1, true ]

How can I solve this?

Answer

Open 2 cmd windows at your QuickStart directory.

Window #1:

npm run build:watch

then,

Window #2:

npm run serve

It will then open in the browser and work as expected.