Betaflight Configurator is ONLY for Betaflight-capable flight-controllers, not DJI equipment, not Walksnail Equipment, not Radio-Controllers, not anything else.
Recommend latest Configurator 10.10: https://github.com/betaflight/betaflight-configurator/releases
Use data-cable, not charge-cable. not all data-cables are perfect.
USB-C-Only laptops and/or newer FC’s with USB-C often need OTG cable or USB-A to USB-C dapters.
DFU mode is for update/flashing; normal mode is for connect/configurations
Windows: Uninstall any broken drivers in Windows "Device Manager" that have the warning sign "⚠️". (Typically also "Delete the driver software for this device
".)
Windows: "Guillemot STM DFU Device" driver is wrong; please purge: https://oscarliang.com/fc-driver-issues-flash-firmware/#Wrong-DFU-Driver-Installed (Windows "Device Manager">Sound/Video/Game>Uninstall w/ delete toggled)
AT32 chips may require Artery drivers:
OSX: AT32 chip may not connect, try https://app.betaflight.com/
Windows: Often need need ImpulseRC Driver Fixer. https://impulserc.blob.core.windows.net/utilities/ImpulseRC_Driver_Fixer.exe
Physically force DFU mode:
sometimes having RX or other periherals powered on will inhibit flashing. consider desoldering or moving peripheral's power to a LiPo-only powered rail/pad. This is especailly true for some FC using UART1 which may share serial resources with VCP(USB) resources. Maybe consider moving periheral from UART1 onto another.
Sometimes COM port is hidden.
FC needs 5v power from USB-port to work correctly.
Cannot brick an FC: https://youtu.be/Zj24aEOyTWs and other connection/UART talk.
[outdated now] Firmware's fault: 4.4.1 may flash but not connect.
Try a 4.4.*-zulu
or 4.5-zulu
it may be fixed..
DFU hijacking https://betaflight.com/docs/wiki/guides/current/DFU-Hijacking#what-is-dfu-hijacking (Potentially fixed with ImpulseRC Driver Fixer). I've seen this on UART1, UART3, UART5.
Windows: maybe need to disable driver-signing requirements: https://pureinfotech.com/disable-driver-signature-enforcement-windows-11/
Linux setup: https://hackmd.io/@nerdCopter/H1dtIuUSn
Many thanks to RabbitAmbulance, Vitroid, Haslinghuis and other community members for portions of this information.