Unable to add plugins or platform to ionic3 project

As soon as I run command cordova add platform or ionic cordova plugin add https://github.com/moust/cordova-plugin-videoplayer.git I get the error stated below.

(node:5072) UnhandledPromiseRejectionWarning: Unhandled promise rejection (rejec tion id: 1): CordovaError: Cordova does not know add; try cordova help for a l ist of all the available commands. (node:5072) [DEP0018] DeprecationWarning: Unhandled promise rejections are depre cated. In the future, promise rejections that are not handled will terminate the Node.js process with a non-zero exit code.

I tried degrading cordova but it did not work. How do I solve this problem?

need to upgrade your node and npm to latest version it seems… check with it.

Didnt work ! It still gives me same error.

error seems with the commanding u are using

remove your respective platform and add again
ionic cordova platform add ios/android

i have tried every command that is possible… even the one you suggested but it does not solve the problem.

sometimes because of registry settings in windows… might give issues of node… can u check the same with restarting your machine once…

I restarted and it still does not work.