Errors are reported for all projects in eclipse -- Solution for Red Cross Projects

Today, I encountered a very depressing situation. All the new projects in eclipse are highlighted in red. At first, I thought I was probably because I have been configuring the ndk development environment for the past two days, is it because I accidentally configured the place, and then the project will show a Red Cross when creating a new project. Then I cleaned up and suffered a big cake, and all the projects failed.

Open the following error prompt:

The error indicates that debug certificate has expired. Baidu once encountered a similar problem, saying that the time limit of a private key was involved.

Solution:Go to c: \ Documents ents and Settings \ Administrator \. Android to delete: Debug. keystore and ddms. cfg, re-open eclipse, and then clean up.

Note: OpenEclipseOfProblemView (if disabled, you canWindow-> Show ViewFindProblemView), and then you can see the root cause of the project in the view.

Cause Analysis: Android requires allProgramA signature is required. Otherwise, the program will not be installed. During our development process, ADT uses debug keystore and sets it in preference> Android> buid in eclipse. By default, the debug keystore is valid for one year. If you started Android development from a year ago, the debug keystore may expire after one year, this may lead to engineering errors or the inability to generate APK files. (think about the development of Android applications that I started at this time a year ago ).