Like nested classes, it is not possible to reference inherited nested type alias by a child class.

compiler/frontend/src/org/jetbrains/kotlin/resolve/DeclarationsChecker.kt

@@ -717,7 +717,7 @@ class DeclarationsChecker(
     }
 
     private fun checkImplicitCallableType(declaration: KtCallableDeclaration, descriptor: CallableDescriptor) {
-        descriptor.returnType?.let {
+        descriptor.returnType?.unwrap()?.let {
             val target = declaration.nameIdentifier ?: declaration
             if (declaration.typeReference == null) {
                 if (it.isNothing() && !declaration.hasModifier(KtTokens.OVERRIDE_KEYWORD)) {

compiler/testData/diagnostics/tests/typealias/inhreritedTypeAliasQualifiedByDerivedClass.kt

@@ -0,0 +1,13 @@
+// !DIAGNOSTICS: -UNUSED_VARIABLE -UNUSED_PARAMETER
+
+open class Base {
+    typealias Nested = String
+}
+
+class Derived : Base()
+
+fun test(x: Derived.<!UNRESOLVED_REFERENCE!>Nested<!>) = <!DEBUG_INFO_ELEMENT_WITH_ERROR_TYPE!>x<!>
+
+fun Base.testWithImplicitReceiver(x: <!UNRESOLVED_REFERENCE!>Nested<!>) {
+    val y: <!UNRESOLVED_REFERENCE!>Nested<!> = <!DEBUG_INFO_ELEMENT_WITH_ERROR_TYPE!>x<!>
+}

compiler/testData/diagnostics/tests/typealias/inhreritedTypeAliasQualifiedByDerivedClass.txt

@@ -0,0 +1,19 @@
+package
+
+public fun test(/*0*/ x: [ERROR : Derived.Nested]): [ERROR : Derived.Nested]
+public fun Base.testWithImplicitReceiver(/*0*/ x: [ERROR : Nested]): kotlin.Unit
+
+public open class Base {
+    public typealias Nested = kotlin.String
+    public constructor Base()
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
+public final class Derived : Base {
+    public constructor Derived()
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}

compiler/tests/org/jetbrains/kotlin/checkers/DiagnosticsTestGenerated.java

@@ -19539,6 +19539,12 @@ public class DiagnosticsTestGenerated extends AbstractDiagnosticsTest {
                 doTest(fileName);
             }
 
+            @TestMetadata("inhreritedTypeAliasQualifiedByDerivedClass.kt")
+            public void testInhreritedTypeAliasQualifiedByDerivedClass() throws Exception {
+                String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/diagnostics/tests/typealias/inhreritedTypeAliasQualifiedByDerivedClass.kt");
+                doTest(fileName);
+            }
+
             @TestMetadata("isAsWithTypeAlias.kt")
             public void testIsAsWithTypeAlias() throws Exception {
                 String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/diagnostics/tests/typealias/isAsWithTypeAlias.kt");