Outlook may stop responding when you accept a meeting request

When you accept a meeting request in Microsoft Office Outlook 2003 or in Microsoft Office Outlook 2007, Outlook may stop responding (hang).

This behavior may occur if Outlook is running an offline folder (.ost) file in non-Unicode mode on a server that is running Microsoft Exchange Server. If your profile was configured to run in offline mode before you upgraded to Outlook 2003 or to Outlook 2007, you are still using the old .ost file that does not support Unicode, and Outlook is still running in non-Unicode mode on the Exchange server.

Note The Exchange Server version or the policies that were set by your administrator may be preventing Outlook 2003 from running in Unicode mode.

To resolve this behavior, disable the .ost file, and then create a new Unicode .ost file in Outlook. To do this, follow these steps.

Disable the .ost file

To disable an .ost file in Outlook 2003, follow these steps:

1. Manually synchronize your .ost file from the offline folders that appear in the Folder List in Outlook 2003 to the server folders that are on an Exchange server. To do this, use one of the following methods:
   • To synchronize a selected folder, point to Send/Receive on the Tools menu, and then click This Folder.
   • To synchronize all your folders that are set up for offline use, point to Send/Receive on the Tools menu, and then click Send/Receive All.
   • To synchronize Send and Receive group folders, point to Send/Receive on the Tools menu, and then click the name of the Send and Receive group.
2. On the Tools menu, click E-Mail Accounts, click View or change existing e-mail accounts, and then click Next.
3. In the list, click Microsoft Exchange Server, and then click Change.
4. Click More Settings.
5. Click the Advanced tab, and then click Offline Folder File Settings.
6. Click Disable Offline Use.
7. You may have configured Outlook 2003 to prompt you to work online or to work offline when you configured how you work offline. In this case, you can change the setting so that you no longer receive the prompt. To do this, follow these steps:
   1. On the Tools menu, click E-mail accounts, click View or change existing e-mail accounts, click Next, click Microsoft Exchange Server, and then click Change.
   2. Click More Settings, and then click the General tab.
   3. Under When starting, click Automatically detect connection state.
      
      Note To permanently remove the .ost file from your computer, you must delete it.
8. Restart Outlook 2003.

To disable an .ost file in Outlook 2007, follow these steps:

1. Manually synchronize your .ost file from the offline folders that appear in the Folder List in Outlook to the server folders that are on an Exchange server. To do this, use one of the following methods:
   • To synchronize a selected folder, point to Send/Receive on the Tools menu, and then click This Folder.
   • To synchronize all your folders that are set up for offline use, point to Send/Receive on the Tools menu, and then click Send/Receive All.
   • To synchronize Send and Receive group folders, point to Send/Receive on the Tools menu, and then click the name of the Send and Receive group.
2. On the Tools menu, click Account Settings.
3. On the E-mail tab, click the account that is configured to connect to the Exchange server, and then click Change.
4. Click More Settings.
5. Click the Advanced tab, and then click Offline Folder File Settings.
6. Click Disable Offline Use.
7. You may have configured Outlook 2007 to prompt you to work online or to work offline when you configured how you work offline. In this case, you can change the setting so that you no longer receive the prompt. To do this, follow these steps:
   1. On the Tools menu, click Account Settings.
   2. On the E-mail tab, click your Exchange account, and then click Change.
   3. Click More Settings, and then click the General tab.
   4. Under When starting, select Automatically detect connection state.
      
      Note To permanently remove the .ost file from your computer, you must delete it.
8. Restart Outlook 2007.

Create a new .ost file

To create a new .ost file, follow these steps:

1. On the File menu, click Work Offline.
2. Click to select or click to clear the Prompt me at startup so I may choose to work offline or online check box, and then click OK.
   
   If you click to clear the Prompt me at startup so I may choose to work offline or online check box, Outlook will automatically start offline if a connection to the server is not available.
3. Click Yes to copy the data from the server to the new .ost file on your computer.

In Outlook 2003 and in Outlook 2007, a new .ost file format is introduced that offers more storage capacity for items and for folders. Additionally, this format supports multilingual Unicode data.

A file that is created in this new format is not compatible with earlier versions of Outlook, and the file cannot be opened in an earlier version of Outlook.

Outlook 2003 and Outlook 2007 automatically determine the format that the .ost file is created in based on the version of the Exchange server, the administrator settings, and the formats of the data files that are configured for the profile. If the settings do not permit the file to be created in the new format, Outlook 2003 or Outlook 2007 create the file in the format that is compatible with an earlier version of Outlook. This format does not support Unicode. Additionally, this format offers the same storage capacity that was available in the earlier versions of Outlook.

When Outlook 2003 or Outlook 2007 run in non-Unicode mode on the Exchange server, the code page-based system is used for character mapping. In a code page-based system, a character that is entered in one language may not map to the same character in another language. Therefore, you are likely to see incorrect characters, including question marks (?), when Outlook 2003 or Outlook 2007 run in non-Unicode mode on the Exchange server.

For example, consider two people. One person is running the English version of the Microsoft Windows XP operating system with the Latin code page. The second person is running the Japanese version of the Windows XP operating system with the Japanese code page.

The second person creates a meeting request in the Japanese version of Microsoft Outlook 2002, and then sends the request to the first person. When the person who is using the English version of Outlook 2002 opens the meeting request, the code points of the Japanese code page are mapped to unexpected or to nonexistent characters in the Latin script. The text is unintelligible. Therefore, in multilingual environments, run Outlook in Unicode mode on the Exchange server.

For more information about scripts and code pages, see the Outlook Help files.

You might not share e-mail messages and items with people who use Outlook on computers that run in other languages. In this case, you can run Outlook in Unicode or non-Unicode mode on an Exchange server.

A disadvantage of running in non-Unicode mode is that the .ost file that is used for the profile will be created in the format that does not offer more storage capacity for items and for folders. Therefore, if the size limit of the .ost file is an issue for you, it is best to run Outlook in Unicode mode on the Exchange server.

However, if you work in a multinational organization, or if you share e-mail messages and items with people who use Outlook on systems that run in other languages, it is best to run Outlook in Unicode mode on the Exchange server. Additionally, when you run Outlook in Unicode mode on the Exchange server, you can be sure that Unicode-capable personal folders (.pst) files are used for a profile that can store multilingual Unicode data.

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