I am using VMware Player to start NetApp simulate ONTAP virtual machine and it keeps restarting. There is a warning message which appears just before is restarts and it says "there do not appear to be any disks attached to the syste, No root volume found."
VMware workstaion player version 15 and Simulate ONTAP version is 9.6
When CTRL+C when the following message is displayed during the boot
********************************
Press Ctrl-C for Boot Menu
*******************************
Then select option 4 "Clean configuration and initialize all disks. "
At the prompt to install a new filesystem press y and at the confirmation prompt press y again. The virtual machine will then restart and reset all the config which should fix your issue.