But the key specification today isn't its speed or range—it's its status. According to D-Link's official technical support announcement, the DSL-124 is a legacy device, and . This means D-Link will no longer develop, repair, maintain, or support the product's firmware or software, including providing bug fixes and security patches.
Check the label on the bottom of your router for the (Hardware Version).
Never attempt a firmware update over Wi-Fi. A temporary wireless drop during the flash process will corrupt the router. Connect your computer directly to the router using an Ethernet (LAN) cable.
This typically indicates a mismatch between the firmware file and your hardware revision: