An error occurred while attaching module (Dynamicweb.Frontend.Content)

System.IO.IOException: codec header mismatch: actual header=-1686489088 vs expected header=1071082519 (resource: MMapIndexInput(path="F:\Domains\Sites\hewitt.mydwsite4.com\Application\wwwroot\Files\System\Indexes\Content\Content builder\ContentIndex\_aa_Lucene41_0.doc"))
   at Lucene.Net.Codecs.Lucene41.Lucene41PostingsReader..ctor(Directory dir, FieldInfos fieldInfos, SegmentInfo segmentInfo, IOContext ioContext, String segmentSuffix)
   at Lucene.Net.Codecs.Lucene41.Lucene41PostingsFormat.FieldsProducer(SegmentReadState state)
   at Lucene.Net.Codecs.PerField.PerFieldPostingsFormat.FieldsReader..ctor(SegmentReadState readState)
   at Lucene.Net.Index.SegmentCoreReaders..ctor(SegmentReader owner, Directory dir, SegmentCommitInfo si, IOContext context, Int32 termsIndexDivisor)
   at Lucene.Net.Index.SegmentReader..ctor(SegmentCommitInfo si, Int32 termInfosIndexDivisor, IOContext context)
   at Lucene.Net.Index.StandardDirectoryReader.FindSegmentsFileAnonymousClass.DoBody(String segmentFileName)
   at Lucene.Net.Index.SegmentInfos.FindSegmentsFile.Run(IndexCommit commit)
--- End of stack trace from previous location ---
   at Lucene.Net.Index.SegmentInfos.FindSegmentsFile.Run(IndexCommit commit)
   at Lucene.Net.Index.StandardDirectoryReader.Open(Directory directory, IndexCommit commit, Int32 termInfosIndexDivisor)
   at Lucene.Net.Index.DirectoryReader.Open(Directory directory)
   at Dynamicweb.Indexing.Lucene.ReaderWrapper..ctor(String path)
   at Dynamicweb.Indexing.Lucene.LuceneIndexProvider.<>c.b__15_0(String p)
   at System.Collections.Concurrent.ConcurrentDictionary`2.GetOrAdd(TKey key, Func`2 valueFactory)
   at Dynamicweb.Indexing.Lucene.LuceneIndexProvider.GetReaderWrapper()
   at Dynamicweb.Indexing.Lucene.LuceneIndexProvider.SearchInternal(IQuery query, QuerySettings settings)
   at Dynamicweb.Indexing.Querying.QueryService.Query(IQuery query, QuerySettings settings)
   at Dynamicweb.QueryPublisher.Frontend.GetModuleContent()
   at Dynamicweb.Frontend.Content.GetModuleOutput(Paragraph paragraph, PageView pageview)