I have made a number of changes to my system lately and over the last few months Lightroom has consistently slowed down. This fix seemed to have the greatest impact though I can’t say I see how it could improve performance, it certainly has.
Add administrator permissions to the following folders or files (CMD-I on folders or files)
1) Go> Go to Folder: /Library
- Logs/Adobe
- Caches/com.adobe.LightroomClassicCC7
- preferences/com.adobe.lightroomClassicCC7.plist
- Application supports/Adobe/Lightroom CC
2) Go> Go to Folder: /users
- Users/Shared/Adobe
3) Purge cache (launch Lightroom and go into Preferences)
Lightroom> Preferences>Performance
- Camera Raw Cache Settings: Purge Cache (click that button)
- View Cache Settings: Purge Cache (click that button)
4) Optimize Catalogue (within Lightroom)
File> Optimize Catalog