Ionic cordova android emulate failed Running command - failed!

ionic project works fine, but when i want to test cordova plugins like facebook plugings for example it does not work.

running “ionic cordova android emulate” shows this error
ionic cordova emulate android

cordova platform add android --save
× Running command - failed!
[ERROR] Exception: Using cordova-fetch for cordova-android@~6.2.2

ionic cordova build

? What platform would you like to build (android, ios): android

cordova platform add android --save
× Running command - failed!
[ERROR] Exception: Using cordova-fetch for cordova-android@~6.2.2