Jonathan Altman

Ran across this today, and didn't find anything while googling for it so figured I would capture it for posterity and in case it happens to me again.

I went to update Android SDK to the latest version today and it was not appearing after pulling down the latest manifests from the web.  It was stuck on the last version released (in this case, version 21 was the latest released, but 20 was the version installed on my machine).  Even worse, some parts of API version 17 showed up in my list of installable packages, but not all of them and not Android SDK Tools or the main SDK Platform.

Solution: go to the Android SDK Manager menu->Preferences.  In the Manifest Cache section on the preferences screen there is a button on the right that says "Clear Cache".  Clicking that button, then closing preferences and selecting Package->Reload from the app menu and all the latest package manifests show up.