When I go to Android SDK Manager from eclipse and trying to Install new packages it doesn't allow me to install any of them.
Most of these new packages depends on installing "Android API 17 SDK platform". But the "Android API 17 SDK platform" doesn't load in the list on the Android SDK Manager for me to install.
Following is a screenshot of the message it displaying to avoid installation.
Would be grateful if someone can guide me through this. Thanks.
Clear the Cache under Tools ---> Options or disable it entirely. I've had problems before with packages not showing because of Cache.
After that Make sure the correct Sites are enabled and the Filters under Packages are correct. Then Reload the List or Restart SDK Manager.
Your still using Platform tools v12, the current one is v16. Probably because of Cache you cant update the tools and in the old tools some things wont show at all. If none of this works install the current v21 SDK with v16 Platform tools from the Android developer homepage.
This is probably a form of this known issue in R20:
http://tools.android.com/knownissues
"Explanation: The SDK Manager in Tools 20.0.0 now has a cache mechanism -- it keeps a local copy of small manifest XML files to perform a faster start when opened. There's also a mechanism to automatically update the cache. However in Tools 20.0.0 and 20.0.1, that refresh is broken and in some conditions the manager will not show new tools that are available unless a reload is performed. Clearing the SDK Manager cache or manually forcing a reload forces the manager to get the latest manifest."
Maybe yo should uncheck the "Show" "Installed" at the left bottom, and it shouldshow "SDK Platform".
Try to reload the sdk manager from Packages -> Reload. and then try to install the sdks.
来源：https://stackoverflow.com/questions/14956688/android-sdk-manager-doesnt-load-the-latest-android-sdk-platform-api-17