How to modify the Web.config file to show more detailed error messages in Microsoft CRM

Applies to: Dynamics CRM 4.0Microsoft CRM client for Microsoft Office OutlookMicrosoft Business Solutions CRM Sales for Outlook

This article describes how to modify the web.config file to show more detailed error messages in Microsoft Dynamics CRM 4.0, in Microsoft Dynamics CRM 3.0, in Microsoft CRM 1.2, and in Microsoft Business Solutions CRM 1.0.

More Information


You can receive more detailed (debug) error messages in one or more of the following products:
  • The Microsoft Dynamics CRM Web client
  • The Microsoft CRM 1.2 Sales for Outlook client (the Outlook client)
  • The Microsoft Dynamics CRM client for Microsoft Office Outlook
You can modify either or both of the Web.config files that are in the Microsoft CRM deployment. We do not recommend that you use debug error messages in production environments. However, you may find these messages useful when you try to debug a problem that occurs in Microsoft CRM.

To modify the Web.config file, follow these steps:
  1. In Windows Explorer, locate the Web.config file.
    • If you are receiving errors in the Microsoft Dynamics CRM Web client, modify the Web.config file that is located on the Microsoft Dynamics CRM server. By default, this file is located in one of the following folders:
      <system drive>:\inetpub\wwwroot

      <system drive>:\Program Files\Microsoft Dynamics CRM\CRMWeb
    • If you are receiving errors in the Microsoft CRM 1.2 Sales for Outlook client, modify the Web.config file that is located on the client computer. By default, this file is located in the following folder:
      <system drive>:\Program Files\Microsoft CRM\Client\res\Web

      Note This option is unavailable in the Microsoft CRM 1.0 Sales for Outlook client.
    • If you are receiving errors in the Microsoft CRM desktop client for Microsoft Office Outlook or in the Microsoft Dynamics CRM online client for Microsoft Office Outlook, modify the Web.config file that is located on the Microsoft CRM server. By default, this file is located in one of the following folders:
      <system drive>:\inetpub\wwwroot
      <system drive>:\Program Files\Microsoft Dynamics CRM\CRMWeb
    • If you are receiving errors in the Microsoft CRM laptop client for Microsoft Office Outlook or in the Microsoft Dynamics CRM offline client for Microsoft Office Outlook, modify the Web.config file that is located on the client computer. By default, this file is located in the following folder:
      <system drive>:\Program Files\Microsoft CRM Client\res\Web
  2. Open the file by using Notepad or another text editing program.
  3. In the file, scroll down the text toward the end of the file to find the following statement:
    <add key="DevErrors" value="Off"/>
    By default, this value is set to Off. Modify this line to read as follows:
    <add key="DevErrors" value="On"/>
    Then, save the file.
  4. After you modify the Web.config file on the Microsoft Dynamics CRM server, close the error window, and then retry the same action that resulted in the previous error message. You should receive a more detailed (debug) error message.
  5. After you use the detailed (debug) error message to troubleshoot, repeat steps 1 through 4 to change the value of the statement back to the default setting of Off. The statement now reads as follows:
    <add key="DevErrors" value="Off"/>
  6. Save the file.
This article was TechKnowledge Document ID:27228