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:
1

Download Kamari Studio

Download the launcher here.
2

Run Studio

Extract the zip file and inside run the file RobloxStudioBeta.exe. If you experience any issues, follow these steps.
3

Login

Log in by attempting to publish a place, or clicking sign up on the welcome page.