“Default Activity Not Found” on Android Studio upgrade

Question

I upgraded IntelliJ Idea from 12.0.4 to 12.10.

Now all the modules in my Android project give the error:

Error: Default Activity Not Found

Answer 1

As this question is a "landing page" for plethora of issues with manifest, resulting in no Default Activity found, here is another thing to check if you are having this problem.

Open your Manifest and switch to Merged Manifest tab.

Sometimes the issue is related to merging all the manifests in the project to one, which can result to error and therefore "Default Activity not found". The problem is this error is not shown anywhere except this Merged Manifest tab as far as I know.

Es: in a project minSdkVersion 10, downgrade the version of implementation in build.gradle file: from 25.4.0 to 25.3.1 solve this problem.

dependencies {
implementation 'com.android.support:appcompat-v7:25.3.1'   
implementation 'com.android.support:design:25.3.1'         
implementation 'com.android.support:mediarouter-v7:25.3.1'