I agree. I think this was the main part of the solution for me as well.    ... View more

As a side note,  now that the serial key has been validated, I can now open Lightroom 6 normally from my MacOS app library without the Creative Cloud app. I uninstalled the Creative Cloud app, and Lightroom 6 still launches perfectly fine.  ... View more

Thanks for your reply and insight!  I'm not sure if something could have changed in the way that Lightroom 6 serial keys are validated or not, but at least in my experience last night I didn't encounter any indication that my Lightroom 6 installation was converted to a subscription version. Neither were there any dialog boxes saying anything about a 30 day trial or an option to subscribe to Creative Cloud. 😄 I did try for a couple of weeks actually to solve the "Please connect to the internet to validate your serial number option." but the resources on the Adobe help page didn't solve the issue in my specific case.  Here are some screenshots from my installation last night in case they are helpful to anyone.  ... View more

I believe that I finally got my standalone copy of Lightroom 6 installed and activated on a new (to me) Macbook pro 2017. I took some steps from another user here and got stuck, but I think I found the right procedure from installing from scratch.  1. I downgraded to a clean install of MacOS Mojave. 2. I used this link https://prodesigntools.com/adobe-cc-2015-updates-links-mac.html#lightroom to download the Lightroom 6 DMG file "Adobe Lightroom 6.14 + CC 2015.14Complete ** 12/19/2017" 3. I used the dowloaded installer, signed in to Adobe, input my serial key, and ran into the "connect to the internet" message. I chose "connect later" and it proceeded with the Lightroom 6 installation. 4. I then installed the latest version of the Creative Cloud from the Adobe website.  Here's where I got stuck. I kept trying to open the Lightroom app from my MacOS library, but I would run into the same "connect to the internet" message. I found I can't launch the Lightroom 6 app from the MacOS shortcut. 5. Close Lightroom and the PDApp, open the new Creative Cloud App; and Lightroom 6 should appear in the Creative Cloud launcher app library as "Lightroom Classic". 6. Open this "Lightroom Classic" (which is actually the Lightroom 6 that you just installed) and it should present you with a new serial key validation dialog that activates and opens Lightroom 6. ... View more

 In order to follow the steps outlined in the post I replied to above.  ... View more

Thanks for the instructions. I have downloaded the file, and have tried to install it on my computer, but when I get to put in my serial number, I receive a message saying that I need to "connect to the internet." I have a stable wifi connection, and access to adobe servers, so there is some other issue. Has any fix been discovered to get past this point?  I tried @Kieran24746206fca4 recommendation above (though with the latest LR 6 install DMG, not the original 6.0 file). "Please connect to the internet to validate your serial number." Is the block I can't seem to get past.  ... View more

Thanks, I couldn't find the Lightroom 6.0 file there though. When I follow the older (before 6.14) links, I get a 404 error. Perhaps Adobe took them down?     ... View more

Thanks @Kieran24746206fca4  for outlining the steps you took to get LR 6 back up and running! Can I ask where you guys got the original Lightroom 6.0 install file?  And the 6.14 patch file? I can't find them anywhere... All I see is the LS11 dmg on the "support is ending" page.  ... View more