Things that worked for me.

1. I turned off my stickC and booted it just as the flashing process is about to happen.

2. Use the old fashioned way, flashing with esptool. Download the latest firmware from our engineers github page https://github.com/EeeeBin/UIFlow-Firmware/tree/beta and get esptool from espressifs github page https://github.com/espressif/esptool
   It will tell you there how to install esptool and pyserial which are necessary for flashing. Once installed, open a terminal and go to the folder of the firmware you downloaded. enter the stick c firmware folder and there will be a flash.sh file, this script will flash the firmware to your device, but you need to make sure it has the correct usb device name written in the script or it will fail. By default it will have written USB_SLABtoUART, but stickc usually has a different named com port.

Give it a go, any issues come back here and ask

My install steps:

1. First, I press Erase button.
2. Second, I press Burn button & got following message:

esptool.py v2.5.0
Serial port COM3
Finished
Command:
--chip esp32 --port COM3 --baud 921600 --before default_reset --after no_reset write_flash -z --flash_mode dio --flash_freq 80m --flash_size detect 0x1000 bootloader_0x1000.bin 0x10000 MicroPython_0x10000.bin 0x8000 partitions_mpy_0x8000.bin 0xf000 phy_init_data_0xf000.bin 0x170000 spiffs_image_0x170000.img

[1948] Failed to execute script esptool
esptool.py v2.5.0
Serial port COM3
Traceback (most recent call last):
File "esptool.py", line 2849, in <module>
File "esptool.py", line 2842, in main
File "esptool.py", line 2549, in main
File "esptool.py", line 213, in init
File "site-packages\serial_init.py", line 88, in serial_for_url
File "site-packages\serial\serialwin32.py", line 62, in open
serial.serialutil.SerialException: could not open port 'COM3': PermissionError(13, '�s���Q�ڡC', None, 5)
The computer is not communicating with the M5Stack. it could be the lead, or the driver but I suspect its the driver as windows requires a specific install method.

1. First, I press Erase button.
2. Second, I press Burn button & got following message:

esptool.py v2.5.0
Serial port COM3
Finished
Command:
--chip esp32 --port COM3 --baud 921600 --before default_reset --after no_reset write_flash -z --flash_mode dio --flash_freq 80m --flash_size detect 0x1000 bootloader_0x1000.bin 0x10000 MicroPython_0x10000.bin 0x8000 partitions_mpy_0x8000.bin 0xf000 phy_init_data_0xf000.bin 0x170000 spiffs_image_0x170000.img

[1948] Failed to execute script esptool
esptool.py v2.5.0
Serial port COM3
Traceback (most recent call last):
File "esptool.py", line 2849, in <module>
File "esptool.py", line 2842, in main
File "esptool.py", line 2549, in main
File "esptool.py", line 213, in init
File "site-packages\serial_init.py", line 88, in serial_for_url
File "site-packages\serial\serialwin32.py", line 62, in open
serial.serialutil.SerialException: could not open port 'COM3': PermissionError(13, '�s���Q�ڡC', None, 5)