Lots of errors in Android Project on opening Eclipse

Question

I created and built my android project successfully. I close the Eclipse and reopen it and have lots of errors. I clean and refresh and rebuild my project but the error is not disappeared.

I open project properties (Alt+Enter), change the project build target to any other API and apply it and again I select my previous API and click OK.

Now everything is OK and my project is built successfully.

Why? Why the build target is not selected after opening the Eclipse and I have to reselect it?

How can I solve it permanently?

Answer 1

I think you should check your "AndroidManifest.xml".

Edit:

You should check if SDK versions

<uses-sdk android:minSdkVersion="19" android:targetSdkVersion="19" /> 

are in the existing installed APIs.