ClassFileAPI related.
Parsing a particular class file to build a ClassModel throws an NPE. Following is the code snippet:
 
        ClassModel cm = ClassFile.of().parse(bytes);
        byte[] newBytes = ClassFile.of().build(cm.thisClass().asSymbol(),
                classBuilder -> {
                    for (ClassElement ce : cm) {
                        if (ce instanceof ClassFileVersion) {
                            classBuilder.with(ClassFileVersion.of(66, 0));
                        } else {
                            classBuilder.with(ce);
                        }
                    }
                });
The file is a valid and verifiable (JVM) file. The stack trace is:
java.lang.NullPointerException: Cannot invoke "java.lang.constant.ClassDesc.isArray()" because "this.sym" is null
              at java.base/jdk.internal.classfile.impl.StackMapGenerator$Type.getComponent(StackMapGenerator.java:1391)
              at java.base/jdk.internal.classfile.impl.StackMapGenerator.processBlock(StackMapGenerator.java:503)
              at java.base/jdk.internal.classfile.impl.StackMapGenerator.processMethod(StackMapGenerator.java:440)
              at java.base/jdk.internal.classfile.impl.StackMapGenerator.generate(StackMapGenerator.java:317)
              at java.base/jdk.internal.classfile.impl.StackMapGenerator.<init>(StackMapGenerator.java:243)
              at java.base/jdk.internal.classfile.impl.StackMapGenerator.of(StackMapGenerator.java:156)
              at java.base/jdk.internal.classfile.impl.DirectCodeBuilder$4.generateStackMaps(DirectCodeBuilder.java:331)
              at java.base/jdk.internal.classfile.impl.DirectCodeBuilder$4.tryGenerateStackMaps(DirectCodeBuilder.java:340)
              at java.base/jdk.internal.classfile.impl.DirectCodeBuilder$4.writeBody(DirectCodeBuilder.java:382)
              at java.base/jdk.internal.classfile.impl.UnboundAttribute$AdHocAttribute.writeTo(UnboundAttribute.java:914)
              at java.base/jdk.internal.classfile.impl.CodeImpl.writeTo(CodeImpl.java:157)
              at java.base/jdk.internal.classfile.impl.AttributeHolder.writeTo(AttributeHolder.java:56)
              at java.base/jdk.internal.classfile.impl.DirectMethodBuilder.writeTo(DirectMethodBuilder.java:156)
              at java.base/jdk.internal.classfile.impl.BufWriterImpl.writeList(BufWriterImpl.java:207)
              at java.base/jdk.internal.classfile.impl.DirectClassBuilder.build(DirectClassBuilder.java:181)
              at java.base/jdk.internal.classfile.impl.ClassFileImpl.build(ClassFileImpl.java:113)
              at java.base/java.lang.classfile.ClassFile.build(ClassFile.java:329)