problem flashing sermoon d1

[B4c4rdi]

Hello guys, I need help updating the firmware for the Sermoon D1.
I don't know much about this flashing, so I'll try to explain as much as possible about the problem.

I have already retrofitted a Bltouch in the past and connected it to the mainboard. Therefore, the starting point of the printer is as follows:

HW version: 4.3.1
Firmware: 1.0.9
DP: DWIN 1.1.15

I now had the following in mind:
Now that clever people have finally managed to get the M600 running (big thanks), I just wanted to flash the "firmware_SermoonD1_BLT_DW7.4.6.bin.zip" version.

1. unzipped
2. copied to sd card (fat32 etc.)
3. pushed into the sd slot of the MB
4. printer switched on

Now to the problem, the printer has started flashing and is only making 20% progress.
I then had no choice but to flash the 1.0.9 version again.

can someone please help me so I can get the new FW on it?

best regards and sry for my bad english