DEM it is unavailable?

Are you sure you do not have some data saver options active, that prevent GCM from downloading the data? 

Now you're just making stuff up...

gaijin said:

Now you're just making stuff up...

Well, there must be a reason why it does not work with you, while it works for others.. Inability to download the data is the first thing that comes to the mind. If you have a better idea, let us know.

... another possibility might be if you have no space remaining on the watch for downloading the DEM data, but the changes in size that I could observe after the DEM calibration were not dramatic. You could perhaps try clearing the Activity folder anyway.

DEM is now working on my Instinct after doing a soft reset, however now the watch takes a long time to find GPS. In system about it says EPO expired, I have followed the support guidance of synching with connect several times, another soft reset, took both phone and watch outside and calibrated using GPS, did a workout, came back synced my run, checked and it still says EPO expired. Next step is to connect to a computer and follow the guidance I guess

Tom said:

I have followed the support guidance of synching with connect several times,

For updating the ephemeris data (EPO) you actually have to use Garmin Express and the USB cable, similarly like for most other updates. It does not seem to be working over Garmin Connect, although it perhaps should. 

Thanks again for your help.  I will have to dust off and power up the the old Windows 7 Laptop and give it a go.