Blinking Cursor when booting Windows 10 on bootcamp

Hello, I have a 21.5'' late 2011 iMac with MacOs Sierra 10.12.6.

This is my problem: my Windows 10 Bootcamp partition stopped booting while i was trying to expand it. It gives me a black screen with a blinking cursor:

My MacOs is working fine though... also the option to boot on the bootcamp partition is no longer present in the disk selection screen (the one that appears while holding command when powering up the iMac)

I tried to run on a Live Windows installation usb:

"Bootrec.exe /fixMbr",

"Bootrec.exe /fixboot" and

"Bootrec.exe /fixRebuildBcd"

but /fixboot returns me "Access Denied" and "/fixRebuildBcd" it's not working either

This is my mounted EFI Volume tree using these commands from this discussion:Can't resize Macintosh HD partition

The commands:

"sudo mkdir -p /Volumes/EFI"

"sudo mount -t msdos /dev/disk0s1 /Volumes/EFI"

"ls -lR /Volumes/EFI"

The output:

total 190

-rwxrwxrwx
1 user
staff
96512 30 Ott 13:57 BOOTLOG

drwxrwxrwx
1 user
staff 512 13 Nov
2014 EFI

/Volumes/EFI/EFI:

total 1

drwxrwxrwx
1 user
staff
512
9 Ago
2016 APPLE

/Volumes/EFI/EFI/APPLE:

total 3

drwxrwxrwx
1 user
staff
512
2 Feb
2015 CACHES

drwxrwxrwx
1 user
staff
512 13 Nov
2014 EXTENSIONS

drwxrwxrwx
1 user
staff
512 17 Ott 23:27 FIRMWARE

/Volumes/EFI/EFI/APPLE/CACHES:

/Volumes/EFI/EFI/APPLE/EXTENSIONS:

total 30722

-rwxrwxrwx
1 user
staff
15729264 30 Ott 15:41 Firmware.scap

/Volumes/EFI/EFI/APPLE/FIRMWARE:

total 16514

-rwxrwxrwx
1 user
staff
8454768 17 Ott 23:27 IM121_004F_00B.scap

I think it's an EFI related problem, can someone help me please?

Thank you