Adobe has prepared this - if your Lightroom is a part of CC -
https://helpx.adobe.com/x-productkb/policy-pricing/activate-deactivate-products.html >>> Deactivate an app >>> Creative Cloud, Acrobat DC >>> I quote:
- Make sure your computer is connected to the Internet.
- Launch the app.
- Choose Help > Sign Out.
- Click Sign Out.
Tip: For more detailed instructions on activating Creative Cloud apps and services, see Sign in and sign out to activate Creative Cloud apps.
Running into a problem? See Activation and deactivation troubleshooting.
If you are using Stand-alone version of Lightroom please Contact Customer Care
If using Lightroom CC,It you have exceeded the activation limits you will be prompted to sign out from the computer.
I have this same problem however the solution does not work in my case. My Lightroom is stand-alone. I have read all the previous threads and followed the links. However when I got to phone customer care it tells me that phone contact not available for my Lightroom "product" ??
Am particularly worried because firstly the SSD drive on my laptop died and had to be replaced. Secondly I got a new chip, motherboard and RAM for my desktop and the cloning did not work so have had to re-install all of my programs one by one.
Help please !