If you create project from remote Git repository the reason may pretty simple : you can get "unable to find valid certification path to requested target" error if you not yet selected SKD in File -> Project Structure -> Project. And not selected in Setttings -> Build,Execution,Deployment-> BuildTools-> (Maven or Gradle "Use project SDK"). Then close project and open again. That error message becouse certs allredy in your sdk, but you don't select your sdk.