c:\server\MobileApp\A\myapp>cordova plugin add cordova-plugin-firebase
Installing "cordova-plugin-firebase" for android
Error during processing of action! Attempting to revert...
Failed to install 'cordova-plugin-firebase': Error: Uh oh!
EPERM: operation not permitted, unlink 'c:\server\MobileApp\A\myapp\platforms\android\app\src\main'
    at Object.unlinkSync (fs.js:1136:3)
    at mayCopyFile (c:\server\MobileApp\A\myapp\node_modules\fs-extra\lib\copy-sync\copy-sync.js:59:8)
    at onFile (c:\server\MobileApp\A\myapp\node_modules\fs-extra\lib\copy-sync\copy-sync.js:54:10)
    at getStats (c:\server\MobileApp\A\myapp\node_modules\fs-extra\lib\copy-sync\copy-sync.js:48:44)
    at startCopy (c:\server\MobileApp\A\myapp\node_modules\fs-extra\lib\copy-sync\copy-sync.js:38:10)
    at handleFilterAndCopy (c:\server\MobileApp\A\myapp\node_modules\fs-extra\lib\copy-sync\copy-sync.js:33:10)
    at Object.copySync (c:\server\MobileApp\A\myapp\node_modules\fs-extra\lib\copy-sync\copy-sync.js:26:10)
    at copyFile (c:\server\MobileApp\A\myapp\platforms\android\cordova\lib\pluginHandlers.js:223:12)
    at install (c:\server\MobileApp\A\myapp\platforms\android\cordova\lib\pluginHandlers.js:61:13)
    at ActionStack.process (c:\server\MobileApp\A\myapp\node_modules\cordova-common\src\ActionStack.js:56:25)
Uh oh!
EPERM: operation not permitted, unlink 'c:\server\MobileApp\A\myapp\platforms\android\app\src\main'