Using a PC on Windows 7. I upgraded from LR5 to 6. When cards inserted under LR5, LR automatically started up with no issues. It will not open now. I have spent time on line with a M/S Windows tech, and he could not help. Windows settings seem fine: Autoplay setting shows LR6. However, LR6 does not show up as a Default Program in the Control Panel listing. In LR, I have checked the "Show Import Dialogue when memory card is detected". I'm stumped.
How can I restore Lightroom to automatically open with the files when I insert my SD or CF card?
Please remove Lightroom 5 from your system and reset the Preferences for Lightroom 6
Navigate to the preferences file:
Mac OS: /Users/[user name]/Library/Preferences/com.adobe.Lightroom5.plist
Windows 7, 8: C:\Users\[user name]\AppData\Roaming\Adobe\Lightroom\Preferences\Lightroom 5 Preferences.agprefs
Drag the preferences file to the Recycle Bin (Windows) or Trash (Mac OS).
Once Open the Lightroom 6 and then check the option as below in the Screenshot "Show Import Dialogue when memory card is detected"
Restart Lightroom and see how it works.
Let us know if it helps.