cloud foundry "incorrect usage" error when trying to push node.js app on windows

I am trying to push an app to cloud foundry. I have gotten this to work in the past, but this is the first time I am doing it after installing cloudfoundry manually.

After navigating to my folder with the file that launches my app, called server.js, I type the following command:

cf push --command "node server.js"

I get the response:

paul@PAUL_LAPTOP /c/users/paul/projects2/meadowlark (master)
$ cf push --command "node server.js"
Incorrect Usage.

no details are provided, which makes this very hard to debug. I used this exact same syntax before and it worked fine. Any idea what might be causing this error.

Any help is appreciated.

Thanks,

Paul