ADDITIONAL SYSTEM INFORMATION :
Host Name: CLM-AUS-T2VVQE
OS Name: Microsoft Windows Server 2016 Standard
OS Version: 10.0.14393 N/A Build 14393
OS Manufacturer: Microsoft Corporation
OS Configuration: Standalone Server
OS Build Type: Multiprocessor Free
Registered Owner: rnd user

A DESCRIPTION OF THE PROBLEM :
java.lang.NullPointerException
        at jdk.compiler/com.sun.tools.javac.api.JavacTrees.attributeDocReference(JavacTrees.java:454)
        at jdk.compiler/com.sun.tools.javac.api.JavacTrees.getElement(JavacTrees.java:414)
        at jdk.javadoc/jdk.javadoc.internal.doclets.toolkit.util.CommentHelper.getElement(CommentHelper.java:179)
        at jdk.javadoc/jdk.javadoc.internal.doclets.toolkit.util.CommentHelper$3.visitReference(CommentHelper.java:460)
        at jdk.javadoc/jdk.javadoc.internal.doclets.toolkit.util.CommentHelper$3.visitReference(CommentHelper.java:434)
        at jdk.compiler/com.sun.tools.javac.tree.DCTree$DCReference.accept(DCTree.java:669)
        at jdk.compiler/com.sun.source.util.SimpleDocTreeVisitor.visit(SimpleDocTreeVisitor.java:79)
        at jdk.javadoc/jdk.javadoc.internal.doclets.toolkit.util.CommentHelper$3.visitLink(CommentHelper.java:445)
        at jdk.javadoc/jdk.javadoc.internal.doclets.toolkit.util.CommentHelper$3.visitLink(CommentHelper.java:434)
        at jdk.compiler/com.sun.tools.javac.tree.DCTree$DCLink.accept(DCTree.java:538)
        at jdk.compiler/com.sun.source.util.SimpleDocTreeVisitor.visit(SimpleDocTreeVisitor.java:79)
        at jdk.javadoc/jdk.javadoc.internal.doclets.toolkit.util.CommentHelper.getReferencedElement(CommentHelper.java:477)
        at jdk.javadoc/jdk.javadoc.internal.doclets.toolkit.util.CommentHelper.getReferencedClass(CommentHelper.java:366)
        at jdk.javadoc/jdk.javadoc.internal.doclets.formats.html.HtmlDocletWriter.seeTagToContent(HtmlDocletWriter.java:1004)
        at jdk.javadoc/jdk.javadoc.internal.doclets.formats.html.HtmlDocletWriter$2.visitLink(HtmlDocletWriter.java:1463)
        at jdk.javadoc/jdk.javadoc.internal.doclets.formats.html.HtmlDocletWriter$2.visitLink(HtmlDocletWriter.java:1324)
        at jdk.compiler/com.sun.tools.javac.tree.DCTree$DCLink.accept(DCTree.java:538)
        at jdk.compiler/com.sun.source.util.SimpleDocTreeVisitor.visit(SimpleDocTreeVisitor.java:79)
        at jdk.javadoc/jdk.javadoc.internal.doclets.formats.html.HtmlDocletWriter.commentTagsToContent(HtmlDocletWriter.java:1539)
        at jdk.javadoc/jdk.javadoc.internal.doclets.formats.html.TagletWriterImpl.returnTagOutput(TagletWriterImpl.java:266)
        at jdk.javadoc/jdk.javadoc.internal.doclets.toolkit.taglets.ReturnTaglet.getTagletOutput(ReturnTaglet.java:90)
        at jdk.javadoc/jdk.javadoc.internal.doclets.toolkit.taglets.TagletWriter.genTagOutput(TagletWriter.java:242)
        at jdk.javadoc/jdk.javadoc.internal.doclets.formats.html.HtmlDocletWriter.addTagsInfo(HtmlDocletWriter.java:332)
        at jdk.javadoc/jdk.javadoc.internal.doclets.formats.html.MethodWriterImpl.addTags(MethodWriterImpl.java:206)
        at jdk.javadoc/jdk.javadoc.internal.doclets.toolkit.builders.MethodBuilder.buildTagInfo(MethodBuilder.java:193)
        at jdk.javadoc/jdk.javadoc.internal.doclets.toolkit.builders.MethodBuilder.buildMethodDoc(MethodBuilder.java:140)
        at jdk.javadoc/jdk.javadoc.internal.doclets.toolkit.builders.MethodBuilder.build(MethodBuilder.java:115)
        at jdk.javadoc/jdk.javadoc.internal.doclets.toolkit.builders.ClassBuilder.buildMethodDetails(ClassBuilder.java:393)
        at jdk.javadoc/jdk.javadoc.internal.doclets.toolkit.builders.ClassBuilder.buildMemberDetails(ClassBuilder.java:341)
        at jdk.javadoc/jdk.javadoc.internal.doclets.toolkit.builders.ClassBuilder.buildClassDoc(ClassBuilder.java:145)
        at jdk.javadoc/jdk.javadoc.internal.doclets.toolkit.builders.ClassBuilder.build(ClassBuilder.java:120)
        at jdk.javadoc/jdk.javadoc.internal.doclets.formats.html.HtmlDoclet.generateClassFiles(HtmlDoclet.java:266)
        at jdk.javadoc/jdk.javadoc.internal.doclets.toolkit.AbstractDoclet.generateClassFiles(AbstractDoclet.java:273)
        at jdk.javadoc/jdk.javadoc.internal.doclets.toolkit.AbstractDoclet.startGeneration(AbstractDoclet.java:207)
        at jdk.javadoc/jdk.javadoc.internal.doclets.toolkit.AbstractDoclet.run(AbstractDoclet.java:114)
        at jdk.javadoc/jdk.javadoc.doclet.StandardDoclet.run(StandardDoclet.java:72)
        at jdk.javadoc/jdk.javadoc.internal.tool.Start.parseAndExecute(Start.java:582)
        at jdk.javadoc/jdk.javadoc.internal.tool.Start.begin(Start.java:431)
        at jdk.javadoc/jdk.javadoc.internal.tool.Start.begin(Start.java:344)
        at jdk.javadoc/jdk.javadoc.internal.tool.Main.execute(Main.java:63)
        at jdk.javadoc/jdk.javadoc.internal.tool.Main.main(Main.java:52)

REGRESSION : Last worked in version 11

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
Used javadoc through command line: -classpath<> -d <output directory> -public, -sourcepath <source filesdir> -Xdoclint:none @packages(package file)

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
above command should pass without any nullpointerexception
ACTUAL -
getting NullPointerException

FREQUENCY : always