Null handles and files not found

[Drushel]

I've been using Chilkat for years now without issue, but seeing some odd behavior now. 

I'm looping through a list of subdirectories and for each one looping through and downloading all files contained within.  This works for about nine subdirectories out of 12 before having issues.  Upon trying to download from one particular folder I'm getting a file not found message, though the files are clearly there and the path is absolutely correct (case sensitive and all).  Another folder comes back with a null handle for some reason.  These folders were all created in the same manner, same permissions, etc.  I can manually retrieve and delete files using another FTP client.

Failed download LastErrorText:

ChilkatLog:
  DownloadFileByName:
    DllDate: Nov 24 2010
    UnlockPrefix: REDACTED
    Username: jdrushel
    Component: ActiveX
    SshVersion: SSH-2.0-1.82_sshlib GlobalSCAPE
    SftpVersion: 3
    PreserveDate: 0
    fromFilePath: /REDACTED/test.txt
    toFilePath: \\\\REDACTED\\test.txt
    OpenRemoteFile:
      filename: /REDACTED/test.txt
      access: readOnly
      createDisposition: openExisting
      v3Flags: 0x1
      Sent FXP_OPEN
      StatusResponse:
        Request: FXP_OPEN
        StatusCode: 2
        StatusMessage: File not found
      SshLog:
SFTP> Sending SSH_FXP_OPEN
TRAN> CHANNEL_DATA
TRAN* NumBytes: 51
TRAN< CHANNEL_DATA
SFTP< Received SSH_FXP_STATUS

      retryFilepath: ./REDACTED/test.txt
      filename: ./REDACTED/test.txt
      access: readOnly
      createDisposition: openExisting
 
    v3Flags: 0x1
      Sent FXP_OPEN
      StatusResponse:
        Request: FXP_OPEN
        StatusCode: 2
        StatusMessage: File not found
      SshLog:
SFTP> Sending SSH_FXP_OPEN
TRAN> CHANNEL_DATA
TRAN* NumBytes: 52
TRAN< CHANNEL_DATA
SFTP< Received SSH_FXP_STATUS

      timeToOpenMs: Elapsed time: 32 millisec
    totalTimeMs: Elapsed time: 32 millisec
    Failed.

Null handles:

Code: [Select]

                        string subDirectoryHandle;
                        subDirectoryHandle = SFTP.OpenDir(remotePath + "/" + remoteFile.filename);

                        ChilkatSFtpDir subDirectoryDirListing = new ChilkatSFtpDir();
                        subDirectoryDirListing = SFTP.ReadDir(subDirectoryHandle);


That subDirectoryHandle is usually an integer like 33, 34, etc.  Once it gets down to one particular folder it comes back as null.

Edit:  I've just noticed that the null handle happens upon reaching 10 in the loop of subdirectories.  If I remove one of the first subdirectories it makes it past the one that previously hit the null handle, and now the next one returns null.  Is this a known limitation in the Chilkat library?