18.04 – Please unlock the disk sda5_crypt, New installation from live usb

Absolute Newb. New installation from live USB. 18.04 Desktop with updates, complete disk erasure and encryption.
After blocking the installation slider after installation, I thought it was the cause of the boot of the USB. So I stopped (physically), shot, and activated.
Now, the login screen says: "Please unlock the sda5_crypt drive."
Other info: Windows 7 / Vista was previously on the disc. Install asked a lot of questions on the keyboard.
THX