Error message: "Unable to update public free/busy data" or "No free/busy information could be retrieved"

You may experience any of the following symptoms when you look for the free/busy information of users in Microsoft Exchange Server:

• You may receive the following error message:
  No free/busy information could be retrieved.
• The free/busy information that you retrieve may be incorrect.
• The free/busy information is displayed as slash marks (/) when you place the pointer on slash marks. Additionally, you receive the following error message:
  No free/busy information could be retrieved

Additionally, when you make changes to your Microsoft Outlook calendar, you may receive one of the following error messages. On a computer that is running Microsoft Windows NT, the error message is as follows: On a computer that is running Microsoft Windows 95, the error message is as follows:

Outlook writes directly to the Free/Busy public folder. You receive error messages if one of the following conditions is true:

• You have multiple public folder servers that have replicas of the Schedule + Free/Busy folder in the same site.
• No server in the site has a replica of the Schedule+ Free/Busy public folder.
• The server that contains the replica of the Schedule+ Free/Busy public folder is unavailable.

By default, the Free/Busy public folder is created on the first server in the site.

You can wait for that server to become available (usually this is the first server in the site), or you can perform the following steps to add a replica on your server:

1. Click Start, point to Programs, point to Microsoft Exchange, and then click Microsoft Exchange Administrator.
2. If you are opening Exchange Administrator for the first time, click Browse to select the server that you want to administer, and then click OK.
3. In the navigation pane, select the server container, and then expand the server that contains the free/busy information. (This server is usually the first server in the site.)
4. Under the server branch, expand Public Information Store, and then click Public Folder Resources.
   
   Note In Microsoft Exchange 2000 Server and in Microsoft Exchange Server 2003, expand Public Folder Store under the server branch, and then click Public Folder Instances.
5. In the details pane, double-click Schedule+ Free Busy Information.
6. Click the Replicas tab.
7. In the Replicate folders to list, follow these steps:
   1. Add the server that you want to contain a replica of the free/busy information.
   2. If you see more than one server in the same Exchange site, one server can be removed.
   3. If there are no servers added for any Exchange site, add one server for that Exchange site.

You also see this error message if the client permissions are not set for Default Editor on the Schedule+ Free and Busy public folder. To change the client permissions:

1. Start the Microsoft Exchange Server Administrator program.
2. Expand the Folders container, then expand the System Folders container.
3. Expand the Schedule+ Free Busy container, and click the folder for your site.
4. On the File menu, click Properties.
5. Click the Client Permissions button.
6. Select Editor from the Roles list.
7. Click OK, and then click OK again.