Problem with JPA information extraction

FreeMarker template error (DEBUG mode; use RETHROW in production!):
The following has evaluated to null or missing:
==> entity.entityName [in template "reports/templates/jpa.ftl" at line 114, column 55]

Tip: It's the step after the last dot that caused this error, not those before it.

Tip: If the failing expression is known to be legally refer to something that's sometimes null or missing, either specify a default value like myOptionalVar!myDefault, or use <#if myOptionalVar??>when-present<#else>when-missing</#if>. (These only cover the last step of the expression; to cover the whole expression, use parenthesis: (myOptionalVar.foo)!myDefault, (myOptionalVar.foo)??

FTL stack trace ("~" means nesting-related):

• Failed at: ${entity.entityName} [in template "reports/templates/jpa.ftl" at line 114, column 53]

  ---

Java stack trace (for programmers):

freemarker.core.InvalidReferenceException: [... Exception message was already printed; see it above ...]
at freemarker.core.InvalidReferenceException.getInstance(InvalidReferenceException.java:131)
at freemarker.core.EvalUtil.coerceModelToString(EvalUtil.java:355)
at freemarker.core.Expression.evalAndCoerceToString(Expression.java:82)
at freemarker.core.DollarVariable.accept(DollarVariable.java:41)
at freemarker.core.Environment.visit(Environment.java:324)
at freemarker.core.MixedContent.accept(MixedContent.java:54)
at freemarker.core.Environment.visitByHiddingParent(Environment.java:345)
at freemarker.core.IteratorBlock$IterationContext.executeNestedBlockInner(IteratorBlock.java:240)
at freemarker.core.IteratorBlock$IterationContext.executeNestedBlock(IteratorBlock.java:220)
at freemarker.core.IteratorBlock$IterationContext.accept(IteratorBlock.java:194)
at freemarker.core.Environment.visitIteratorBlock(Environment.java:572)
at freemarker.core.IteratorBlock.acceptWithResult(IteratorBlock.java:78)
at freemarker.core.IteratorBlock.accept(IteratorBlock.java:64)
at freemarker.core.Environment.visit(Environment.java:324)
at freemarker.core.MixedContent.accept(MixedContent.java:54)
at freemarker.core.Environment.visitByHiddingParent(Environment.java:345)
at freemarker.core.ConditionalBlock.accept(ConditionalBlock.java:48)
at freemarker.core.Environment.visit(Environment.java:324)
at freemarker.core.MixedContent.accept(MixedContent.java:54)
at freemarker.core.Environment.visit(Environment.java:324)
at freemarker.core.Environment.process(Environment.java:302)
at freemarker.template.Template.process(Template.java:325)
at org.jboss.windup.reporting.freemarker.FreeMarkerIterationOperation.perform(FreeMarkerIterationOperation.java:132)
at org.jboss.windup.reporting.freemarker.FreeMarkerIterationOperation.perform(FreeMarkerIterationOperation.java:35)
at org.jboss.windup.config.operation.iteration.AbstractIterationOperation.perform(AbstractIterationOperation.java:65)
at org.jboss.windup.config.operation.GraphOperation.perform(GraphOperation.java:24)
at org.ocpsoft.rewrite.config.DefaultOperationBuilder$DefaultOperationBuilderInternal.perform(DefaultOperationBuilder.java:54)
at org.jboss.windup.config.operation.Iteration.perform(Iteration.java:263)
at org.jboss.windup.config.operation.Iteration.perform(Iteration.java:203)
at org.ocpsoft.rewrite.config.RuleBuilder.perform(RuleBuilder.java:168)
at org.jboss.windup.config.RuleSubset.perform(RuleSubset.java:250)
at org.jboss.windup.exec.WindupProcessorImpl.execute(WindupProcessorImpl.java:140)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:601)
at org.jboss.forge.furnace.proxy.ClassLoaderInterceptor$1.call(ClassLoaderInterceptor.java:87)
at org.jboss.forge.furnace.util.ClassLoaders.executeIn(ClassLoaders.java:42)
at org.jboss.forge.furnace.proxy.ClassLoaderInterceptor.invoke(ClassLoaderInterceptor.java:103)
at org.jboss.windup.exec.WindupProcessorImpl_$$javassist_77ced924-f50d-415d-b944-13cd4287b2b9.execute(WindupProcessorImpl$$_javassist_77ced924-f50d-415d-b944-13cd4287b2b9.java)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:601)
at org.jboss.forge.furnace.proxy.ClassLoaderAdapterCallback$2.call(ClassLoaderAdapterCallback.java:123)
at org.jboss.forge.furnace.util.ClassLoaders.executeIn(ClassLoaders.java:42)
at org.jboss.forge.furnace.proxy.ClassLoaderAdapterCallback.invoke(ClassLoaderAdapterCallback.java:96)
at org.jboss.windup.exec.WindupProcessor_$$javassist_7b29f65c-b098-492c-b9fb-75c4235ec44c.execute(WindupProcessor$$_javassist_7b29f65c-b098-492c-b9fb-75c4235ec44c.java)
at org.jboss.windup.bootstrap.commands.windup.RunWindupCommand.runWindup(RunWindupCommand.java:209)
at org.jboss.windup.bootstrap.commands.windup.RunWindupCommand.execute(RunWindupCommand.java:53)
at org.jboss.windup.bootstrap.Bootstrap.executePhase(Bootstrap.java:286)
at org.jboss.windup.bootstrap.Bootstrap.run(Bootstrap.java:165)
at org.jboss.windup.bootstrap.Bootstrap.main(Bootstrap.java:95)

This error appears on a page for a specific persistent-unit, and the persistence.xml lists entity classes. There were no warning or error message emitted during Windup analysis.