Indexing is failing since last 3-4 days with no changes to the server -

13:33:05.279 [email@domain.com] Error indexing user: System.IndexOutOfRangeException: Index was outside the bounds of the array.
   at System.Collections.Generic.Dictionary`2.Insert(TKey key, TValue value, Boolean add)
   at Lucene.Net.Support.IO.FileSupport.GetCanonicalPath(FileSystemInfo path)
   at Lucene.Net.Store.FSDirectory..ctor(DirectoryInfo path, LockFactory lockFactory)
   at Lucene.Net.Store.FSDirectory.Open(DirectoryInfo path, LockFactory lockFactory)
   at MailService.SearchIndex.Indexing.UserIndexer.IndexUser(UserIndexItem userIndexItem, IndexingContext context, String username, String domainName, PendingIndexDeletions pendingDeletions, Log log)

We have tried restarting SmarterMail, IIS, entire server. The indexing logs are 10-20GB per day filled with above errors.

When will SmarterMail stop sending out buggy releases ? What is the solution to this issue ?