Execution failed for task ':simpleDemo:processDebugMainManifest'. > Manifest merger failed with multiple errors, see logs

The "Manifest merger failed with multiple errors" error message indicates that there are conflicts between the AndroidManifest.xml files of different modules in your project.

To resolve this issue, you can try the following steps:

1. Check the error logs for more information about the specific conflicts in the manifest file. You can find the error logs in the "Messages" view of Android Studio.

2. Once you have identified the conflicting elements in the manifest files, you can use the `<tools:replace>` tag to resolve the conflicts. For example, if two modules have conflicting `<uses-permission>` elements, you can use the following code in the manifest file of the module that you want to keep the permission:

<uses-permission android:name="android.permission.INTERNET" />
<uses-permission tools:node="remove" android:name="android.permission.INTERNET" />

This code will remove the conflicting `<uses-permission>` element from the merged manifest.

3. If you are still unable to resolve the conflicts, you can try merging the manifest files manually. To do this, you need to create a new file called "AndroidManifest.xml" in the "main" folder of your project. Then, you can copy the relevant elements from the manifest files of the different modules into this file, resolving any conflicts manually.

I hope this helps! Let me know if you have any other questions.