SI-8575, see https://issues.scala-lang.org/browse/SI-8575

bug.scala

class E[F]
class A
class B
class C

trait TypeMember {

  type X
 
  id(value) // This call throws an AbstractMethodError
 
  def value: X
  def id(x: X): X
}
 
object TypeMemberTest {
  
  type F = A with B
  
  object Test extends TypeMember {
  
    type X = E[F with C]
    
    // works if replaced by:
    //    type X = E[A with B with C]
    //
    // See `comparison.diff` for a byte code comparison

    val value = new E[F with C]
    def id(x: X) = x
  } 
}

trait TypeParam[X] {

  id(value)
 
  def value: X
  def id(x: X): X
}

// Equivalent code with type params works
object TypeParamTest {

  type F = A with B
  
  object Test extends TypeParam[E[F with C]] {
    val value = new E[F with C]
    def id(x: E[F with C]) = x
  }
}

comparison.diff

--- <unnamed>
+++ <unnamed>
@@ -1,4 +1,4 @@
-// Working version
+// Broken version
 
 Compiled from "bug.scala"
 public class TypeMemberTest$Test$ implements TypeMember {
@@ -21,32 +21,24 @@
        0: aload_1       
        1: areturn       
 
-  public java.lang.Object id(java.lang.Object);
-    Code:
-       0: aload_0       
-       1: aload_1       
-       2: checkcast     #27                 // class E
-       5: invokevirtual #29                 // Method id:(LE;)LE;
-       8: areturn       
-
   public java.lang.Object value();
     Code:
        0: aload_0       
-       1: invokevirtual #33                 // Method value:()LE;
+       1: invokevirtual #27                 // Method value:()LE;
        4: areturn       
 
   public TypeMemberTest$Test$();
     Code:
        0: aload_0       
-       1: invokespecial #34                 // Method java/lang/Object."<init>":()V
+       1: invokespecial #28                 // Method java/lang/Object."<init>":()V
        4: aload_0       
-       5: putstatic     #36                 // Field MODULE$:LTypeMemberTest$Test$;
+       5: putstatic     #30                 // Field MODULE$:LTypeMemberTest$Test$;
        8: aload_0       
-       9: invokestatic  #42                 // Method TypeMember$class.$init$:(LTypeMember;)V
+       9: invokestatic  #36                 // Method TypeMember$class.$init$:(LTypeMember;)V
       12: aload_0       
-      13: new           #27                 // class E
+      13: new           #38                 // class E
       16: dup           
-      17: invokespecial #43                 // Method E."<init>":()V
+      17: invokespecial #39                 // Method E."<init>":()V
       20: putfield      #20                 // Field value:LE;
       23: return        
 }