Problem with MRCC FW update

[BruenMusic]

Hi there,

I tried updating my MRCC from FW version v 1.1.052 to v 1.1.075, but have issues.
I opened the hex file in the Teensy loader. Click on the Auto button (lights up bright green, like in the instructions). The Blue light is lit on the MRCC and then I push the recessed FW button on the MRCC. The blue light will go off and ... nothing happens. The unit is on, but can't excess anything. When powercycling it does boot. For clarity: No I did not use the FW of the NDLR.

I used the Teensy loader both on Windows 10 and on Mac OS (Sierra).
What am I missing? Or am I missing a step? 

Here's what the LOG-file says:

15:52:52.826 (loader): Teensy Loader 1.58, begin program
15:52:52.944 (loader): File "C:\Users\Marco\Downloads\MRCC\MRCC_v1.1.075_08-23-2023.hex_\MRCC_v1.1.075_08-23-2023.hex", 268648 bytes
15:52:52.945 (loader): File "MRCC_v1.1.075_08-23-2023.hex". 268648 bytes
15:52:52.956 (loader): Listening for remote control on port 3149
15:52:52.956 (loader): initialized, showing main window
15:52:53.193 (loader): HID/win32:  vid:046D pid:C52B ver:1203  usb:0/140000/0/5/6
15:52:53.193 (loader): HID/win32:  vid:046D pid:C52B ver:1203  usb:0/140000/0/5/6
15:52:53.193 (loader): HID/win32:  vid:046D pid:C52B ver:1203  usb:0/140000/0/5/6
15:52:53.194 (loader): HID/win32:  vid:046D pid:C52B ver:1203  usb:0/140000/0/5/7
15:52:53.194 (loader): HID/win32:  vid:046D pid:C52B ver:1203  usb:0/140000/0/5/7
15:52:53.194 (loader): HID/win32:  vid:046D pid:C52B ver:1203  usb:0/140000/0/5/7
15:53:04.804 (loader): Open File event
15:53:17.532 (loader): File "C:\Users\Marco\Downloads\MRCC\MRCC_v1.1.075_08-23-2023.hex_\MRCC_v1.1.075_08-23-2023.hex", 268648 bytes
15:53:17.532 (loader): File "MRCC_v1.1.075_08-23-2023.hex". 268648 bytes
15:53:19.588 (loader): Auto Button event
15:53:19.588 (loader): Auto mode: enabled
15:53:32.424 (loader): Verbose Info event