Thanks for reaching out. We are sorry for the trouble with Adobe Lightroom. We are here to help.
Could you please confirm if this has started to happen recently, or is it the first time you have launched Lightroom on this machine? Do you use a VPN or any other protective/antivirus software that may interfere with the internet configuration of your device?
Before further troubleshooting, we must ensure you have all the data backed up locally or on the cloud.
You can log on to Lightroom Web (https://lightroom.adobe.com) to check and confirm everything is synced.
Try these steps:
Go to the following location
- C:\Users\<Username>\AppData\Local\Adobe\Lightroom CC
- Press the Windows > Enter 'Run' > Type %localappdata%\Adobe
- Rename the Lightroom CC folder as 'Lightroom CC.old' (add .old at the end)
- Restart Lightroom.
Let us know how it goes.