Change the upgrade type to "User DB" or "Channel List" and select the file.
This specific version ( DatabaseV66 ) is typically tied to a specific firmware generation. Loading a database version that does not match your firmware can sometimes lead to "Invalid File" errors or system hangs.
Because these files are specific to regional satellite configurations (e.g., Nilesat, Hotbird, Astra), they are primarily found on enthusiast forums and manufacturer support pages:
The is a specific channel list file (database) used for digital satellite receivers equipped with the NationalChip GX6605H chipset. These receivers often run the ECOS operating system and are popular for Free-To-Air (FTA) broadcasts. Technical Overview of the .sdx File