When has just started up the encrypted VM cannot be opened and it stays inaccessible. Also, the encrypted VM stays inaccessible if it was just registered without a password or the password is incorrect. The user needs to provide the password using or with the following VBoxManage command:

VBoxManage encryptvm uuid|vmname addpassword --password filename|- --password-id ID
                  

To supply the encryption password point VBoxManage to the file where the password is stored or specify - to let VBoxManage prompt for the password on the command line.

If ID is the same as the password identifier supplied when encrypting the VM it updates the accessibility state.

To remove the entered password from the VM memory, use VBoxManage as follows:

VBoxManage encryptvm uuid|vmname removepassword ID
                  

If ID is the same as the password identifier supplied when encrypting the VM it updates the accessibility state.