Launchpad is one of the best feature in Mac OS X 10.7 or later. You can use launchpad by pressing launchpad icon or three finger thumb on Mac trackpad. But some Mac users complained about launchpad issue.
Fix 1: Check scroll direction is natural or not
Go to Apple menu -> System Preferences -> Trackpad.
Select Scroll & Zoom tab and check Scroll direction set to natural. If it not set to natural, set it to natural.
Fix 2: Reset MacBook Pro launchpad to the default layout
Open the Terminal app from utility folder or using Spotlight search.
Type or paste the following command in terminal.
defaults write com.apple.dock ResetLaunchPad -bool true; killall Dock
Then press the Return or Enter key.
Fix 3: Check your Mac Trackpad performance
Check your Mac trackpad performance. Maybe this issue might be happened because of the high CPU usage issue. Close Google Chrome and remove unwanted files.
Fix 4: Repair or Reinstall Mac OS X
Check if your computer running slow or not? If you installed any other OS like Windows on Mac using Bootcamp, then launch OS and check Trackpad performance.
If your MacBook Air trackpad working well in Windows, then repair Mac OS X Yosemite using Disk Utility.
Fix 5: Report your Mac problem in Apple Support communities
If you can’t fix your Mac trackpad issue, create a new thread for your issue in Apple support communities. A lot of Mac geeks available there.