You may still be on the older version of our npm modules. When you run 'pac install latest', this upgrades your CLI version so that you are using the latest, but the version of npm module that you use is governed by the package.json file in your PCF projects.
One change that we announced with this update is that you should change the related devDependencies lines in the package.json file of your PCF projects.
Now, while in the directory of your project, you can run 'npm update' to get the latest npm modules. To verify, open up the node_modules directory, scan down to 'pcf-start' and open the package.json file in that module's directory. If you have the current version, you will see:
A brand new PCF control using the dataset template will by default not have anything to render in the control harness. To visualize a dataset control in the harness you can refer to one of the sample dataset controls that have been published with the public preview.