Bootcamp Windows 10 Installation - No bootable device -- insert boot disk and press any key

Hello everyone,

I have an 13" macbook pro mid 2012 which runs MacOS Catalina. I wanted to dual boot my 750GB hard drive (not SSD) to run Bootcamp Windows 10 Pro and MacOS. I went through the Bootcamp assistant, and it all went smoothly. It installed the ISO image onto my HP V210W 16GB flash drive, along with the support files. Then, the computer restarted.

I have installed Bootcamp on my macbook Pro before so I know what should have come up. The Windows 10 Setup screen should have showed up on the macbook pro Screen after restarting.

HOWEVER, when the macbook pro restarts, it shows the normal white screen, and then it shows a black screen that says "No bootable device -- insert boot disk and press any key". I am not sure why this happened.

So next I try to circumvent this issue by restarting, holding Alt/Option, and it brings up the boot order page. The options are "Macintosh HD", "Windows", and "EFI". I select the Windows option. It brings me back to my original problem with the black screen and the "no bootable device" message.

Next, I try to instead start up with the EFI option. This successfully enters the Windows setup, but when I progress through all of the steps, at the step where I select which partition to install Windows on, it tells me that "Windows cannot be installed to this disk. The selected disk has an MBR partition table. On EFI systems, Windows can only be installed to GPT disks." Now, I sort of knew that this was going to come up because Mac usually uses an MBR partition, but it is arranged in a BIOS system for Windows to use. If I use EFI, like I selected before, it will want a GPT disk format.

So now I am officially stuck. I have no clue what to do, and I have researched everywhere on this problem. I do not have anything but the keyboard, mouse, and USB flash drive connected to the macbook pro.

I tried with different USB 2 flash drives but no use.

If anyone could help me with this, that would be great.

Thanks.