Error updating maps on Fenix 6X - "There was an error installing the update".

Just unboxed my new Fenix 6X.

Using Garman Express I updated several software packages on the watch to the latest version. Then tried updating the maps using Express and got:


"There was an error installing the update"


Express connects and starts to download then after about 5 mins the above message comes up. Anyone any ideas?

Thanks