According to the spec,

In a value class, a blank final instance variable must be definitely assigned after the argument list of an explicit superclass constructor invocation (8.8.7.1).

Link: https://cr.openjdk.org/~dlsmith/jep401/jep401-20240624/specs/value-objects-jls.html#jls-8.3.1.2
 
                Test Code:
                value class ValueClass {
                  int f;
 
                 {
                        f = 7;
                 }
 
                 public int get() { return f; }
              }
                
                The Valhalla java runtime throws the below error. In jdk23, normal class this final field was initialized successfully.
 
                PS C:\SivaG\Official\JavaProject\src> java --enable-preview TestCls
Exception in thread "main" java.lang.VerifyError: Illegal use of putfield on a strict field
Exception Details:
                Location:
                ValueClass.<init>()V @7: putfield
                Reason:
                Error exists in the bytecode
                Bytecode:
                 0000000: 2ab7 0001 2a10 07b5 0007 b1
 
                at TestCls.main(TestCls.java:16)