So what happens when you use the menu Help > Sign In ? Do that, and then go to the Preferences, Mobile tab.
The Help menu shows I'm signed in. I've already attempted to Sign out and sign back in with no change in the ability to use Lightroom mobile from my desktop.
Have you tried resetting your preferences? I would suggest you follow the instructions at How to set Lightroom preferences to find the preferences file and make a copy of it before deleting.
Another thing to try is removing the Sync.lrdata file, which is the hidden database containing sync data.
- On Mac it's at /Users//Library/Caches/Adobe/Lightroom/Sync Data/Sync.lrdata
- On Win it would be at C:\Users\\AppData\Local\Adobe\Lightroom\Caches\Sync Data\Sync.lrdata
2 people found this helpful
While neither of the suggested items fixed it, I went a step further and removed the entire C:\Users\\AppData\Local\Adobe\Lightroom\ folder which solved the problem.
Thanks for your help John!