I installed Parrot Security os-4.8 twice on virtualbox on my MacBook Air (2015), and after successful installation with no errors (both times), after rebooting virtualbox, again I get the option to use it as live or install with other options that appears as if the OS is not installed. I checked the vdi and it appears to be of 6gb in size(I think the OS is still there).
Any suggestions? Thanks in advance.(sorry for bad English)
It sounds like you did not download the Virtual Image File ( OVA File)
( Your English is great BTW )
go to - https://parrotlinux.org/download/
Next -Go to the Virtual Tab
Download This Image
Click on the OVA file after download to import into Virtual Box
IMPORTANT NOTE - the default password and super user password for this machines image is - toor