Error installing 2nd version of Linux Mint: The attempt to mount a file system ... at /boot/efi failed

The device I'm currently working on, is pre-installed Windows 10 with legacy BIOS. I have two bootable drives with both contain Linux Mint installer in it. - the first drive contains Mint 19 - the second is Mint 21. I made both using same method, and I've already verified each ISO file before I burned them. I can successfully install the Mint 19 from my first drive to my device with no issue at all. But when I'm trying to install Mint 21 from my second drive, i got the error saying The attempt to mount a file system with type vfat in SCSI1 (0,0,0), partition #1 (sda) at /boot/efi failed. It comes up right after the partitioning section. Anyone have any ideas about this issue? My guess is that the different version of the installer (ubiquity? - not sure, though) acts differently from its earlier version. My questions are: - Is it possible to move only *the files that contains the Linux Mint 21* from my second drive to my first drive but retain the rest files for the installation purpose from the mint 19? In other words, I want to install Mint 21 but using the installer from Mint 19 in my first USB drive? - Which files I have to replace from my USB drive to do so?