All new projects in ADT Eclipse are all red-cross solutions

Eclipse New Project all have Red fork, clean, restart has been no use, on the Internet to see a lot of, think this method is good.

the meaning of the error: Debug Certificate expired for the sake of.

Workaround :

1. Enter: C:\Documents and settings\administrator\. Android

2. Delete: Debug.keystore and ddms.cfg re-open Eclipse and then clean cleanup will be OK.

Note: Open the problem view of eclipse (if you have closed the problem view under Window->show view), and then in the view you can see the root cause of the project.

cause Analysis : Android requires that all programs must have a signature, otherwise the program will not be installed. In our development process, ADT uses debug KeyStore, which is set in Preference->android->buid in Eclipse. Debug KeyStore is valid for one year by default, and if you started Android a year ago, it's likely that debug KeyStore expires a year later, causing engineering errors or inability to generate apk files, and so on.

All new projects in ADT Eclipse are all red-cross solutions