Android - Include layout from another module -

i have module called testguilib , have specified testview.xml simple framelayout.

<framelayout xmlns:android="http://schemas.android.com/apk/res/android"     xmlns:app="http://schemas.android.com/apk/res-auto"     android:layout_width="match_parent"     android:layout_height="match_parent">      <textview         android:id="@+id/textview"         android:layout_width="wrap_content"         android:layout_height="wrap_content"         android:text="testing view!" />  </framelayout> 

i tried use layout in main app activity_main. here code:

<?xml version="1.0" encoding="utf-8"?> <android.support.constraint.constraintlayout xmlns:android="http://schemas.android.com/apk/res/android"     xmlns:app="http://schemas.android.com/apk/res-auto"     xmlns:tools="http://schemas.android.com/tools"     android:layout_width="match_parent"     android:layout_height="match_parent"     tools:context="com.example.sam.testapp1.mainactivity">      <textview         android:layout_width="wrap_content"         android:layout_height="wrap_content"         android:text="hello world!"         app:layout_constraintbottom_tobottomof="parent"         app:layout_constraintleft_toleftof="parent"         app:layout_constraintright_torightof="parent"         app:layout_constrainttop_totopof="parent" />      <include layout="@layout/testview"         android:layout_width="wrap_content"         android:layout_height="wrap_content"         app:layout_constraintleft_toleftof="parent"         app:layout_constraintright_torightof="parent"         />  </android.support.constraint.constraintlayout> 

everything works fine. compiles ok , runs ok. preview doesn't work. shows blank screen (ie. when clicked on "design", turns blank) render errors:

could not find layout resource matching value 0x7f04002f (resolved name: testview) in current configuration.

also, there line under testview (ie. include layout="@layout/testview"). when rolled mouse over, said

typo in word 'testview'

spellchecker inspection helps locate typos , misspelling in code, comments , literals, , fix them in 1 click.

any idea? thanks

go "file > invalidate caches/restart...", click "invalidate , restart". should work.