The current Kamari Studio release is a development release, some features such as play testing, and team create do not work/function as expected. We are working on a new release that will fix these issues.
You can install Kamari Studio on your system by following these steps:
Download Kamari Studio
Download the launcher here. Run Studio
Extract the zip file and inside run the file RobloxStudioBeta.exe. If you experience any issues, follow these steps. Login
Log in by attempting to publish a place, or clicking sign up on the welcome page.