I have the above error and have no clue why I still have it. I have reinstalled API 23 numerous times and done googling and the only fix I found was to reinstall the API but sti
I am using Ubuntu ,and I had the same issue. The accepted answer did not work for my version of Android Studio (2.3.3).
I had to import an Eclipse webapp project for Android SDK 15, and did receive the same message. The solution that worked for me was the following:
"~/[user_xxx]/Android/Sdk/platforms/".