Unable to make directory: Documents. Result is 2

Hi, When I use the command "appbuilder livesync" after successfully executed "appbuilder build ios --companion", I am getting following error.
Unable to find adb in PATH. Default one from appbuilder resources will be used.
Unable to make directory: Documents. Result is 2
Error: Future resolved more than once
    at Object.Future.return (/usr/local/lib/node_modules/appbuilder/node_modules/fibers/future.js:313:10)
    at Socket.<anonymous> (/usr/local/lib/node_modules/appbuilder/lib/common/mobile/ios/ios-core.js:709:30)
    at Socket.emit (events.js:95:17)
    at Socket.<anonymous> (_stream_readable.js:764:14)
    at Socket.emit (events.js:92:17)
    at emitReadable_ (_stream_readable.js:426:10)
    at emitReadable (_stream_readable.js:422:5)
    at readableAddChunk (_stream_readable.js:165:9)
    at Socket.Readable.push (_stream_readable.js:127:10)
    at Pipe.onread (net.js:528:21)

Any suggestions?
Thanks.