It appears the last Lightroom update is pretty buggy. At least so much buggy that Adobe decided to post about it:
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