It seems your plugin will need to get some attention if you want it to be supported on TFS11, because of this piece of code that targets an url that no longer exists:

public String getUrl(@NotNull String host, @NotNull String id) {

    return appendTrailingSlash(host) + "tfs/web/wi.aspx?id=" + id;
}

Might be a better option to consume the TFS API instead.