Never update firmware over Wi-Fi. A signal drop can brick the device.
D-Link manages firmware downloads through regional support portals. It is safest to use the official source to avoid malware or corrupted files. Dap-1360 Firmware 6.10 Download
If the interface says "Invalid Image," double-check your H/W revision on the bottom sticker. Never update firmware over Wi-Fi
Locate the 6.10 download link, usually provided as a .bin or .zip file. Step-by-Step Installation Guide Dap-1360 Firmware 6.10 Download
Select "F1" (or your specific revision) from the dropdown list.
Perform a factory reset by holding the Reset button for 10 seconds while the device is powered on.