My app doesn't run neither on device nor on emulator

When I enter command:
ionic cordova run android
everythings goes fine then the process terminates showing these warnings:

(node:1896) UnhandledPromiseRejectionWarning: SyntaxError: Unexpected token in JSON at position 0
** at JSON.parse ()**
** at Function.PlatformJson.load (C:\Users\Ahsan\AppData\Roaming\npm\node_modules\cordova\node_modules\cordova-common\src\PlatformJson.js:34:21)**
** at Function.restoreMissingPluginsForPlatform (C:\Users\Ahsan\AppData\Roaming\npm\node_modules\cordova\node_modules\cordova-lib\src\cordova\prepare.js:159:37)**
** at C:\Users\Ahsan\AppData\Roaming\npm\node_modules\cordova\node_modules\cordova-lib\src\cordova\prepare.js:95:31**
** at Array.map ()**
** at Function.preparePlatforms (C:\Users\Ahsan\AppData\Roaming\npm\node_modules\cordova\node_modules\cordova-lib\src\cordova\prepare.js:83:31)**
** at C:\Users\Ahsan\AppData\Roaming\npm\node_modules\cordova\node_modules\cordova-lib\src\cordova\prepare.js:64:39**
** at _fulfilled (C:\Users\Ahsan\AppData\Roaming\npm\node_modules\cordova\node_modules\cordova-lib\node_modules\q\q.js:787:54)**
** at self.promiseDispatch.done (C:\Users\Ahsan\AppData\Roaming\npm\node_modules\cordova\node_modules\cordova-lib\node_modules\q\q.js:816:30)**
** at Promise.promise.promiseDispatch (C:\Users\Ahsan\AppData\Roaming\npm\node_modules\cordova\node_modules\cordova-lib\node_modules\q\q.js:749:13)**
(node:1896) UnhandledPromiseRejectionWarning: Unhandled promise rejection. This error originated either by throwing inside of an async function without
a catch block, or by rejecting a promise which was not handled with .catch(). (rejection id: 1)
(node:1896) [DEP0018] DeprecationWarning: Unhandled promise rejections are deprecated. In the future, promise rejections that are not handled will terminate the Node.js process with a non-zero exit code.

Can anyone help me in finding out what’s going on?