Assertion failed in SortUtility

Getting an assert failure in SortUtility. Plan is attached. Stack trace below:

Caused by: java.lang.AssertionError: Assertion failed.
at org.teiid.core.util.Assertion.failed(Assertion.java:73)
at org.teiid.core.util.Assertion.assertTrue(Assertion.java:68)
at org.teiid.core.util.Assertion.assertTrue(Assertion.java:60)
at org.teiid.query.processor.relational.SortUtility.<init>(SortUtility.java:145)
at org.teiid.query.processor.relational.SortNode.sortPhase(SortNode.java:96)
at org.teiid.query.processor.relational.SortNode.getFinalBuffer(SortNode.java:180)
at org.teiid.query.processor.relational.RelationalPlan.getFinalBuffer(RelationalPlan.java:307)
at org.teiid.query.processor.QueryProcessor.getFinalBuffer(QueryProcessor.java:239)
at org.teiid.query.processor.BatchCollector.collectTuples(BatchCollector.java:137)
at org.teiid.dqp.internal.process.RequestWorkItem.processMore(RequestWorkItem.java:374)
at org.teiid.dqp.internal.process.RequestWorkItem.process(RequestWorkItem.java:287)
... 37 more