Seems that Yammer recently changed their OAuth 2.0 authentication process to require the OAuth 2.0 token in an Authorization: Bearer token rather than as a query string as it used to be: http://developer.yammer.com/authentication/ (under "Making API requests"). I think it was announced at some point in Yammer's Developer Network but can't find it anymore.
Nevertheless, this means that the current implementation of passport-yammer is broken and it no longer works. It's a tiny fix that I already have in place :), so a pull request is coming in shortly.
Seems that Yammer recently changed their OAuth 2.0 authentication process to require the OAuth 2.0 token in an Authorization: Bearer token rather than as a query string as it used to be: http://developer.yammer.com/authentication/ (under "Making API requests"). I think it was announced at some point in Yammer's Developer Network but can't find it anymore.
Nevertheless, this means that the current implementation of passport-yammer is broken and it no longer works. It's a tiny fix that I already have in place :), so a pull request is coming in shortly.