I am not sure about your device, but it's possible that the map should be in .system (Please note the dot in front of the word).
However, you are on the safe side if you create a folder "Map" on your device, rename the Indonesia map to anything but "gmapprom" or gmapsupp" and copy it to the Map folder.
You'll find more detailed information in [Only registered and activated users can see links. ]
Cheers
Tom
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