#1212 Assertion Error

[Anonymous]

program.name=DocFetcher
program.version=1.1.18
program.build=20160725-2146
program.portable=false
java.runtime.name=Java(TM) SE Runtime Environment
java.runtime.version=1.7.0_71-b14
java.version=1.7.0_71
sun.arch.data.model=32
os.arch=x86
os.name=Windows 7
os.version=6.1
user.language=en
java.lang.AssertionError: net.sourceforge.docfetcher.model.index.IndexingQueue: RefCount is 0 pre-decrement for file "_a.tii"
at org.apache.lucene.index.IndexFileDeleter$RefCount.DecRef(IndexFileDeleter.java:624)
at org.apache.lucene.index.IndexFileDeleter.decRef(IndexFileDeleter.java:514)
at org.apache.lucene.index.IndexFileDeleter.decRef(IndexFileDeleter.java:504)
at org.apache.lucene.index.IndexFileDeleter.checkpoint(IndexFileDeleter.java:467)
at org.apache.lucene.index.IndexWriter.rollbackInternal(IndexWriter.java:2884)
at org.apache.lucene.index.IndexWriter.close(IndexWriter.java:1820)
at org.apache.lucene.index.IndexWriter.close(IndexWriter.java:1786)
at net.sourceforge.docfetcher.model.index.IndexWriterAdapter.close(IndexWriterAdapter.java:101)
at net.sourceforge.docfetcher.model.index.file.SimpleDocWriter.close(SimpleDocWriter.java:54)
at com.google.common.io.Closeables.close(Closeables.java:80)
at com.google.common.io.Closeables.closeQuietly(Closeables.java:99)
at net.sourceforge.docfetcher.model.index.file.FileIndex.doUpdate(FileIndex.java:209)
at net.sourceforge.docfetcher.model.TreeIndex.update(TreeIndex.java:148)
at net.sourceforge.docfetcher.model.index.Task.update(Task.java:98)
at net.sourceforge.docfetcher.model.index.IndexingQueue.threadLoop(IndexingQueue.java:193)
at net.sourceforge.docfetcher.model.index.IndexingQueue.access$100(IndexingQueue.java:46)
at net.sourceforge.docfetcher.model.index.IndexingQueue$2.run(IndexingQueue.java:118)