Android build fails with unknown reason after upgrading android-sdk

Question

I am working with old version Unity 4.0 to use some old plugin. After my wrong step of upgrading Android SDK, Unity gives a error and it doesn't build the Unity project at all.

I read it is the typical error by upgrading Android SDK, rev 21 to rev 22. And it shows

Error building Player: Exception: Android (invocation failed) Error* Unknown error

Then I tried to downgrade Android SDK to rev21, also reinstall Unity and Eclipse(just in case), but all did not work.

Do you have any suggestion to recover this trouble?

According to SDK manager my Android SDK contains:

• Android SDK Tools: Rev.21
• Platform-tools: 19.0.1
• API: 15, 14
• Extras: Android Support Library

Answer 1

似乎无法在\\ androidsdk \\ tools中找到aapt.exe文件，请尝试从\\ androidsdk \\ build-tools \\ 19.0.1（任何版本）中复制aapt.exe。