FWIW, mine ran fine. I would generally try a "run as admin" if it seems like permission problems.

Well everyone, thanks for trying but no luck. I tried running in admin mode, making UAC as tolerant as possible, checking that ad blocker was off, etc. etc.
 
Lynn, how do you update directly from the site? Seems like that might be the answer.
 
Thought I'd get lucky when I found an older version, but it decided it had to update itself and after downloading the update, restarted and gave the same issue, accompanied by an error message (see below). I also get this if I try to load AD2 from within SONAR. Interestingly, on my product page it doesn't show AD2, only AD1.
 

 
Restarted the computer several times, uninstalled XLN online installer and re-installed, uninstalled again and tried the old version...guess I'll wait to see if support gets back to me. Meanwhile, there's always BFD 
 
 

Have you tried reinstalling the XLN Online Installer? https://www.xlnaudio.com/install
 
There was an update for it recently, as well as updates for AD2 and AK. It went fairly smoothly for me, aside from the slow download speeds.
 
I don't recall needing to run it as Admin, but it couldn't hurt.
 

Hi Craig,
 
I know it doesn't help that much, but I just did the update on Windows 7 OS with no problems encountered.  I'm up to date with the latest Platinum version.
 
As for the error message, I have encountered that message (within Sonar) when my installation of XLN products are out of date. Mine was some weird registration problem as a result of a system crash and having to do a system restore.  I think you are running into the domino effect (with Sonar) due to the "installer" not installed correctly or up-to-date (unless you've had some system problems).
 
Syphus

Craig, have you updated graphic card drivers lately?

Craig, I just ran the Installer - I had to unauthorise and re-authorise my PC following the Win 10 upgrade to 1709 before it would work. Good luck.
 

Hi Craig
 
I had an update issue with the installer as well. I contacted support and in my case they quickly replied:
 
"I'm sorry to hear about these issues. File mismatch errors usually indicate problems with the internet connection. The most common cause is an unstable Internet connection, in which case retrying the download should solve the issue. If this is not the case, an antivirus and / or firewall running in the background may be the cause; it may stop the Online Installer from accessing the Internet. Try either adding the Online Installer as a "trusted program" or try disabling them temporarily while running the Online Installer."
 
In my case, seems that the wireless security settings indeed are the issue: At work I cannot update from the public wireless system, whereas from home it still works ok. Still using the same laptop.

Craig, this is where I went to get the latest installer: https://www.xlnaudio.com/install
 
Best of  luck to you.

This could be yet another case of W10 screwing up "what once worked before doesn't work now"  thing. 
 
What I would try is to go find all traces of XLN installer in your system and nuke them. 
Now use the link Lynn posted above and start over. 

Lynn
Craig, this is where I went to get the latest installer: https://www.xlnaudio.com/install
 

Yes, that's where I got it as well. I've re-installed a few times. Will keep trying...thanks everyone for the suggestions.