[Error message] Google Drive quits unexpectedly. [Suggested steps] Go to drive.google.com. Click the Download Google Drive link in the left navigation. Download the most recent version of Google Drive. During the installation, click Yes when you’re asked to replace your current version. Choose a new Google Drive folder and sync your files. [Likely reason] 
There's an error with the version of Google Drive for your Mac/PC that you’ve installed.