Adobe published a notice regarding some critical performance and crasher bugs in the latest Lightroom 2015.2 / 6.2 update:
The Lightroom team wanted to let the community know that we’re investigating some critical performance and crasher bugs, and will be issuing an update shortly to address them. If you are experiencing crashing or slowdowns, please try the following:
- Go to Lightroom > Preferences.
- Click on the General tab
- Uncheck “Show ‘Add Photos’ Screen”
- Restart Lightroom