Simply clicked on Garmin Express to install the map update and with in a few seconds there is red band at the top of Garmin Express saying "There was and error installing the update"
Suspect the issue might be memory related as only 2GB of free space... and does not seem to use the sd card I have put in the slot
Like SUSSAMB indicated we will need more information to better help you. I have looked into your account and found that your device unlocked North America & Europe 2015.40 mapping. I know in the start of this posting you indicated that this is with the NA maps. Did the Europe maps update? The reason I ask this is to determine if the device is communicating correctly and can be written to.
I understand that you hit install and almost right away it fails. So the map is not even starting to download or if you have downloaded it started to check the file it just fails. This failing during stage 1 the download or verification could be a few things. It could be server side issue or possibly Internet connection related. This could also be 3rd part security software causing issues. I have tested the map update using your device information and the update completed successfully.
I would suggest try starting with these FAQ's: What should I do if I am having problems downloading updates in Garmin Express?
and How do I update Garmin Express?
Thanks for you assistance I eventually fixed it... I connected the device to basecamp and noticed for some reason the Europe map appeared twice.
I reinstalled the Europe map which had previously installed correctly then using another computer I started the north America map update and it all worked.
Still not sure what the issue was... But all well and good
