ArrayIndexOutOfBoundException when facet.method= enum is used

Question

I am seeing below exception when facet.method= enum is used. Earlier we got error related to "Too many unique values" for facet.method = fc. so changed it to enum. Anybody is aware of the error ?

field definition in schema file:

<fieldType name="arches_typeahead" class="solr.TextField" omitNorms="true">
800            <analyzer type="index">
801                <tokenizer class="solr.WhitespaceTokenizerFactory"/>
802                <!--  agressively split words -->
803                <filter class="solr.WordDelimiterFilterFactory"
804                        preserveOriginal="1"
805                        generateWordParts="1" generateNumberParts="1" catenateWords="1"
806                        catenateNumbers="1" catenateAll="0" splitOnCaseChange="1"/>
807                <!-- remove garbage and keep alpha-numeric-accent and reserved characters -->
808                <filter class="solr.PatternReplaceFilterFactory" pattern="[^\p{L}\P{M}\p{Nd}\p{Nl}\p{Cs}@$%_#?*+^!~&amp;|(){}\\[\\].'\&quot;/\\\\-]+"
809                        replacement="" replace="all"/>
810                <filter class="solr.TrimFilterFactory"/>
811                <filter class="solr.EdgeNGramFilterFactory" minGramSize="1" maxGramSize="4"/>
812                <filter class="solr.LowerCaseFilterFactory"/>
813            </analyzer>
814            <analyzer type="query">
815                <tokenizer class="solr.KeywordTokenizerFactory"/>
816                <filter class="solr.LowerCaseFilterFactory"/>
817                <filter class="solr.PatternReplaceFilterFactory" pattern="[^\p{L}\P{M}\p{Nd}\p{Nl}\p{Cs}@$%_#?*+^!~&amp;|(){}\\[\\].'\&quot;/\\\\-]+"
818                        replacement="" replace="all"/>
819                <filter class="solr.TrimFilterFactory"/>
820            </analyzer>
821        </fieldType>

[09:55:54] ERROR 3-thread-1 o.a.s.c.SolrCore <> org.apache.solr.common.SolrException: Exception during facet.field: arches_typeahead_text
        at org.apache.solr.request.SimpleFacets$2.call(SimpleFacets.java:598)
        at org.apache.solr.request.SimpleFacets$2.call(SimpleFacets.java:583)
        at java.util.concurrent.FutureTask.run(FutureTask.java:266)
        at org.apache.solr.request.SimpleFacets$1.execute(SimpleFacets.java:537)
        at org.apache.solr.request.SimpleFacets.getFacetFieldCounts(SimpleFacets.java:608)
        at org.apache.solr.request.SimpleFacets.getFacetCounts(SimpleFacets.java:264)
        at org.apache.solr.handler.component.FacetComponent.process(FacetComponent.java:107)
        at org.apache.solr.handler.component.SearchHandler.handleRequestBody(SearchHandler.java:226)
        at org.apache.solr.handler.RequestHandlerBase.handleRequest(RequestHandlerBase.java:135)
        at org.apache.solr.core.SolrCore.execute(SolrCore.java:1976)
        at ariba.arches.search.CoreContainer.initialWarmup(CoreContainer.java:995)
        at ariba.arches.search.CoreContainer$2.run(CoreContainer.java:215)
        at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
        at java.util.concurrent.FutureTask.run(FutureTask.java:266)
        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
        at java.lang.Thread.run(Thread.java:745)
Caused by: java.lang.ArrayIndexOutOfBoundsException: 3152
        at org.apache.lucene.util.FixedBitSet.get(FixedBitSet.java:245)
        at org.apache.solr.search.BitDocSet.exists(BitDocSet.java:165)
        at org.apache.solr.search.SortedIntDocSet.intersectionSize(SortedIntDocSet.java:232)
        at org.apache.solr.search.BitDocSet.intersectionSize(BitDocSet.java:174)
        at org.apache.solr.search.SolrIndexSearcher.numDocs(SolrIndexSearcher.java:2048)
        at org.apache.solr.request.SimpleFacets.getFacetTermEnumCounts(SimpleFacets.java:922)
        at org.apache.solr.request.SimpleFacets.getTermCounts(SimpleFacets.java:453)
        at org.apache.solr.request.SimpleFacets.getTermCounts(SimpleFacets.java:366)
        at org.apache.solr.request.SimpleFacets$2.call(SimpleFacets.java:592)
        ... 16 more

Thanks, Sarita