If you are using Photoshop CS6, then Camera Raw 9.1 is the last version of Camera Raw you will be able to install. See details here:
You should choose the option to edit a copy with Lightroom adjustments. Then Lightroom will generate the TIF or the PSD file and will include all of the Lightroom adjustments you have made. Then you can finish your editing on that file using Photoshop.
I am using the latest version of lighroom and a Mid 2012 MacBook Pro Retina
Considering you are using latest version of Lightroom CC 2015.2.1/ Lightroom 6.2.1
Please follow the below steps.
> Go to Lightroom > Preferences.
> Click on the General tab
> Uncheck “Show ‘Add Photos’ Screen”
> Click on Presets Tab
> Disable Apply auto tone adjustments
> Click on Performance tab
> Disable Use Graphics Processor
> Restart the machine
> Launch Lightroom and check for the issue
Let me know if this helps.