Namespace Reservation Error (Error Initializing Recorder)


It is possible to receive the following error when creating a new WebAii test in a solution that does not already have one, or by opening/modifying a solution that already has a WebAii test in it:



This error is usually seen in the VS plugin, and is caused if a Windows User account that is not an administrator attempts to use Test Studio. This error can occur in the VS plugin even when you are using an Administrative user.


This type of issue is caused by the computer you are using not assigning the rights to the namespace you are creating (within Visual Studio) for the project to the non-admin account. These permissions are reserved for the Sys-Admin (the "root" user) and must be dynamically assigned if another user will be utilizing the namespace.

This information is also covered by Microsoft at the link listed in the error, but we will cover it as well below.

SOLUTION 1: XP and Server 2003

Windows Server 2003 users can skip to the next section (using httpcfg.exe), but Windows XP users will need to install the necessary support tools to do this. This is a free download from Microsoft, and is a manual download (meaning it is not included in other software updates; it is "optional").


After you have the tool downloaded, run the installer for the software and proceed to Adding a Namespace Reservation

Using httpcfg.exe to Add a Namespace Reservation:

  1. Open a command prompt as an Administrator.
  2. In the command prompt window, type in the following (replacing the url in the example below with you url you are receiving in your error message):
    1. httpcfg set urlacl /u {http://+:8000/DesignCanvas/XXXX} /a ACL
    2. Press Enter.
  3. You should see the message HttpSetServiceConfiguration completed with 87.


    1. If you get this message, you should be able to use your project as per normal.
    2. If you do not get this message, review your syntax and make any necessary corrections, then re-attempt.
  5. If you are still having issues adding the namespace, provide us with:
    1. A screenshot of your version of the above error message.
    2. A copy of the syntax you are using to add the reservation.


Once we get the information from 4a and 4b we can review your Namespace Reservation string and help modify it as necessary.

SOLUTION 2: Vista & 7

Windows Vista and 7 users will have it easier, as you can use the already installed netsh to add a Namespace Reservation. To do this:

  1. Open a command prompt window.
  2. In the window type the following:
    • netsh http add urlacl url=http://+:8000/DesignCanvas/XXXX user=DOMAIN\user
    • Caveats:
      1. Make sure you are using the url from your error, and not the url listed in the above example.
      2. Make sure you are using your correct 'DOMAIN' in the user string.
      3. Make sure you are using the correct 'username' in the above user string.
  3. Press Enter.
  4. You should receive the message: URL reservation successfully added.


    1. If you do, you should be able to use your project as normal again
    2. If you do not, modify your syntax to make sure you are using your specific data. If you still experience issue, please let us know the following in a support ticket so we can assist with setting up the string with you:
      1. A screenshot of your version of the above error
      2. A copy of the syntax you are using to add the URL reservation

Windows Vista/7: New URL Each Time Visual Studio Loads

If you go through the above netsh process and find that, after you quit and re-open Visual Studio (or restart the computer), you are given a new namespace URL (ex. first error provided url http://+:8000/DesignCanvas/1234, new error provides http://+:8000/DesignCanvas/5678 or any other new url) in the same error message.


We have found this symptom to be caused by having UAC on and active for an account. To fix this symptom, turn off UAC by doing the following:

  1. Click Start > Control Panel.
  2. If you are in category view, click on Category in the upper-right of the Control Panel window and choose either Large or Small icons. Otherwise proceed to step 3.
  3. Click Action Center.
  4. In the left column, click Change User Account Control settings (there should be a shield next to the line-item).
  5. In the new User Account Control Settings window, move the slider bar down to Never Notify.
  6. If you were already at never notify, you will need to do the following:

    1. Move the slider up to Always Notify.
    2. Click OK.
    3. Restart the computer.
    4. Upon restart, you can now do steps 1-5 above, then step 6 (skip these steps, 5i - 5iv)


  7. Click OK, which should also have a shield on it.
  8. Restart your computer to make save these changes.


After you complete the above, you should not have the issue with a different Namespace error each time the project is launched.