View App Store Download Progress (Downloading Maverick) I'm downloading Mavericks on my Lion, but I don't know how to see the progress. When I go to the purchases tab on the app store, I see a blank button:
Try rebooting.
Quit App Store, open Launchpad, find the partial download of Mavericks installer and click it. This usually resumes a download that was interrupted/paused.
Reset App Store by clicking Reset Application from the debug menu, then reboot and try again.

You can enable the debug menu by running the following command:

defaults write com.apple.appstore ShowDebugMenu -bool true