When I updated my macOS 10.12.6 Sierra to 10.13 High Sierra (on a MacBook Pro 15 inch Late 2011 with an HDD) I tried to convert my Macintosh HD drive to APFS, however, I realised that, when I'm on the boot screen, I don't have the recovery partition and, when I boot with Command+R it appears a Recovery that is unable to unmount Macintosh HD. ¿Any solution to this?