“Debug certificate expired” error in Eclipse Android plugins

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.

                                    OR

In Windows 7 it is at the path

C:\Users\[username]\.android

• goto this path and remove debug.keystore
• clean and build your project.
• A new  debug.keystore will be create