In order for the 2018.0 version to download automatically you must be running version 2017.2 and your support must be current.

From the email you received go to the manual download to obtain the file and install.

As mentioned in my post above I am running 2017.2 and my subscription is up to date.   I did not get an email about the update to 2018.  It was just the notification within Sage itself.

If you are a part of the Sage Accountant's Network you should already have the download. However, if you are not a part of the Network then your roll out may not have arrived as yet. I understood that the roll out to customers started in the middle of October and could last up to two weeks. You could call the sales team at Sage and request the link for the download just to speed up the process.  

You can check C:\Users\Public\Documents\Sage Software\Simply Accounting\Download see if is downloaded, in general you should get a pop up message.  

I am part of the accountant's network.  I checked the folder that Jason mentioned below and the download is not there.   I keep waiting for the pop up message when I close Sage, but it's never shown up.   I think I'll have to contact Sage to find out what's up.

If Sage 50 2017.2 is not fully installed, it is likely that is causing the program not to download the updates.  However, you can also turn of the updates.  Have you checked under Help, About Sage 50...., Support Info, Modify Product Update Settings to see if the program is set to download?

If it still not downloading after Richard's suggestion, I think the best just call Sage 50 support ask for download link.

I had an issue with the small update in July to 2017.2 (the interface thing with 365 office).  I always got an error that Sage was not installed correctly so it never finished the update.  Never had an issue with the program itself since the initial update to 2017.2.  The program is set to automatically download updates.   Will contact Sage to get a link to download 2018

Error: "1327 Invalid Drive: X:\" when attempting to install the Office 365 component update

Usually if you don't install the last update (doesn't get properly installed that is), the program will not download the next one.

I had a problem getting it installed back in July and there was a Knowledgebase article available to help get it installed.  It referenced an invalid drive.  I put the link below but it jumped above.  If this is your issue, you may want to try it and see if that works for you.

Manually download Sage 2018 Canadian Edition installer here:

www.sage.com/.../2018