Before flashing confirm that you have [RAK4631](https://docs.rakwireless.com/Product-Categories/WisBlock/RAK4631/) and not a [RAK4631-R](https://docs.rakwireless.com/Product-Categories/WisBlock/RAK4631-R/) If this is not the case, fear not. The hardware is identical but requires changing the bootloader. Instructions on how to do this are located [here](/docs/getting-started/flashing-firmware/nrf52/convert-rak4631r).
If you are upgrading your NRF52 device from a previous version of Meshtastic rather than starting from scratch, you may need to do a full factory reset of the internal flash memory. Stale data saved by previous versions of the Meshtastic firmware can cause devices to get stuck in a crash loop at startup.
Follow the guide to [factory erase your NRF52](/docs/getting-started/flashing-firmware/nrf52/nrf52-erase) device before continuing to [flash firmware](#flash-firmware).