Xamarin build ERROR : error APT0000: In <declare-styleable> ..., unable to find attribute

Question

I received a project from another developer. I setup my machine. VS-2017 with the required components was already configured.

Android SDK-Manager has the corresponding version installed. Project is configured to compile with Android 7.1 (Nougat).

Starting the build I get one error

1>ERROR : error APT0000: In <declare-styleable> AppBarLayout, unable to find attribute android:keyboardNavigationCluster

It is unclear to me, were I need to set this information, or were this information is needed.

I rececked ERROR: In MenuView, unable to find attribute android:preserveIconSpacing and Error:In SherlockSpinner, unable to find attribute android:popupPromptView. Both articles don't help.

I rechecked the SDK-Tools, I deleted the folder C:\Users\<user>\AppData\Local\Xamarin.

As far as I understand the message there is an attribute missing, that needs to be set.

In a project file Resource.designer.cs I found

public const int AppBarLayout_android_keyboardNavigationCluster = 2;

The name seams to match exactly.

Can someone explain me this error?

Can someone explain how I get rid of it and how to fix similar problems in future?

Answer 1

I had this error and after some research I just installed the Android OREO 8.0 SDK in the Android SDK Manager and than I select Android Project > Properties > Application > Use latest Platform (Android 8.0 (Oreo)). And it worked for me.

Answer 2

You have to update the target of your project, It seems that the solution was created with a higher target (Oreo API Level 26)

Answer 3

I fixed it by setting the Target Android Version to API Level 26.