Android Error – Debug Certificate Expired

One day our project works perfectly, and the next day it shows a red cross. This happens when we’ve been working on the same project for exactly one year. What’s going on is that our certificate has expired, since it’s only valid for one year.

We can see the following error in the “Problems” view:

Error generating final archive: Debug Certificate expired on xx/zz/yy hh:mm

Solution

To fix it, we check where the "debug.keystore" is installed in "Windows / Preferences".

In the sidebar on the right, we select "Android / Build" and look at the path where the keystore is located in "Default debug keystore".

With Eclipse closed, we go to our user folder in Windows and then to the “.android” folder. We find “debug.keystore” and delete it.

When we restart Eclipse, it will generate a new one that will last another year.

But now you’ll get a different error when you try to run an APK (app) on the emulator where it was previously installed with the old certificate. See the error: Different certificate when trying to reinstall the app on the emulator.