lets example -
type Error generating final archive: Debug Certificate expired on 6/13/12 5:36 PM XYZProjectName Unknown Android Packaging Problem
How to resolved Debug certificate expired
1. Delete your debug certificate under ~/.android/debug.keystore on Linux and Mac OS X;
2. Delete your debug certificate like %USERPROFILE%/.androidon Windows.
The Eclipse plugin will automatically generate a new certificate when you next try to build a debug package.
You may need to clean and then build to generate the certificate.
Upon installation, the Android SDK generates a "debug" signing certificate for you in a keystore called debug.keystore.
The Eclipse plug-in uses this certificate to sign each application build that is generated.
Unfortunately a debug certificate is only valid for 365 days.
To generate a new one you must delete the existing debug.keystore file.
Its location is platform dependent - you can find it in Preferences - Android - Build - Default debug keystore.
You can create your own debug certificate in debug.keystore with whatever expiration you want. Do this in the .android folder under your HOME directory:
keytool -genkey -v -keystore debug.keystore -alias androiddebugkey -storepass android -keypass android -keyalg RSA -validity 14000
On Vista, this worked:
DOS: del c:\user\dad\.android\debug.keystore
ECLIPSE: In Project, Clean the project. Close Eclipse. Re-open Eclipse.
ECLIPSE: Start the Emulator. Remove the Application from the emulator.
In Windows 7 it is at the path
goto this path and remove debug.keystore
clean and build your project.
Delete: debug.keystore located in C:\Documents and Settings\[user].android
Restart Eclipse and automatically you will have another keystore
Delete your keystore located in ~/.android/debug.keystore then restart Eclipse.
On Ubuntu, this worked:
I went to home/username/.android and I renamed keystore.debug to keystoreold.debug.
I then closed Eclipse, started Eclipse, and SDK created new certificate keystore.debug in that folder.
You then have to uninstall/reinstall apps you installed via USB Debugging or an unsigned APK ("unsigned" APK = signed with debug certificate).