SBS Err Msg: Unable to Display This Folder

• Microsoft Exchange Windows NT client, version 5.0
• Microsoft Exchange Windows 95/98 client, version 5.0
• Microsoft Outlook Windows NT client, versions 8.03, 8.5
• Microsoft Outlook Windows 95/98 client, versions 8.03, 8.5
• Microsoft Outlook 2000

SYMPTOMS

When you use the Microsoft Exchange Client and/or Microsoft Outlook 97/98 and connect to an Exchange Server hosted on a computer running Microsoft Small Business Server, the client logon attempt may fail with the following error:

Unable to display this folder, there are no additional Microsoft Exchange client licenses available.

Event ID: 201
Source: LicenseService
Type: Error
Description: No license was available for user domain\username using product MSExchangeIS.

CAUSE

During the logon process from a client to the server, there are three connections that are made: one for the actual client (Outlook or Exchange) and two (see NOTE below) for the MAPI spooler. The client connects first and creates a mapped file with the name derived from the server that it is connecting to. The information contained in this file allows multiple connections to be linked and only count as one user. When the MAPI spooler logs on and tries to open this mapped file created by the client connect, the open failed because the file handle was erroneously closed.

This caused the MAPI spooler to create a new mapped file and, therefore, incremented the user count to 2 for every client logon attempt. The MAPI spooler then makes a second connection to the server and tries again to open the mapped file created by the client connect. This open failed as well, leading the MAPI spooler to create yet another mapped file and, therefore, incrementing the user count to 3 for every client logon attempt. As a result, using a 5-user license for Small Business Server would only allow 2 Outlook or Exchange client logon attempts before running out of licenses.

NOTE: The MAPI spooler opening 2 connections to the server was introduced in Exchange Server 5.5 SP1; previous to this, it only opened one. So the number of user connections seen as a result of this problem may fluctuate between 2 or 3, depending on client versions. The number of User Connections can be seen by using Performance Monitor and selecting the User Count counter under the MSExchangeIS object.

RESOLUTION

To resolve this issue, install Microsoft Outlook 2000.

STATUS

Microsoft has confirmed this to be a problem in the Microsoft products listed at the beginning of this article. This problem was first corrected in Exchange Server 5.5 Service Pack 3.

Additional query words: sbsfaqtop XADM XCLN sbs hang SmallBiz Small Business Server 4.5

Keywords : sbsfaqtop EXC55SP3Fix
Version : WINDOWS:2000,5.0,8.03,8.5
Platform : WINDOWS
Issue type : kbbug