Switch IIS Application Pool between 32-bit and 64-bit mode to address 'Class Not Registered' error when loading Network Atlas Maps in SolarWinds Platform 2025.4

Certain legacy features, like Network Atlas maps, rely on 32-bit components and may not display correctly when IIS runs in 64-bit mode. During the upgrade to SolarWinds Platform 2025.4, IIS is automatically upgraded to 64-bit mode if no Network Atlas maps are detected. However, if Network Atlas maps are in use, IIS remains configured in 32-bit mode to maintain compatibility.

Errors:

OrionWeb.log:

2025-10-23 13:19:21,601 [Import cb54de03-d610-422f-be8b-4d72950e82b2.OrionMap] (1253) WARN MapRunner - (null) CreateMapTask(ID=cb54de03-d610-422f-be8b-4d72950e82b2, ObjectType=Map, State=Faulted, Exception=COMException:"Class not registered (Exception from HRESULT: 0x80040154 (REGDB_E_CLASSNOTREG))") failed at Working 

2025-10-23 13:19:21,601 [Import cb54de03-d610-422f-be8b-4d72950e82b2.OrionMap] (1253) ERROR MapRunner - (null)

Network Atlas is dependent on a 32-bit ActiveX COM component.

You can switch the IIS application pool between 32-bit and 64-bit modes using either the IIS Manager graphical interface or the command line.

Note: when IIS has 32 bit mode enabled it is limited in the amount of memory it can use and will cause website latency and stability issues when w3wp.exe is using around 1.5GB of memory. Importing Network atlas maps to intelligent maps and setting the website to 32 bit mode disabled may be the better option.

Import maps

Option 1 – Using IIS Manager (GUI)

1. Open IIS Manager
   Press Win + R, type inetmgr, and press Enter.
2. Navigate to Application Pools
   In the Connections pane on the left, click your server name, then select Application Pools.
3. Select the Application Pool
   Find and select the application pool you want to configure (e.g., SolarWinds Orion Application Pool).
4. Open Advanced Settings
   Right-click the selected application pool and choose Advanced Settings…
5. Modify the "Enable 32-Bit Applications" Setting
   Under the General section, locate Enable 32-Bit Applications and set it to:
   • True to enable 32-bit mode
   • False to enable 64-bit mode
6. Apply Changes and Restart the Application Pool
   Click OK to save changes.
   Then right-click the application pool and select Recycle or Start/Stop to apply the new setting.

Option 2 – Using Command Prompt with appcmd.exe

1. Open Command Prompt as Administrator
   Press Win, search for Command Prompt, right-click it, and select Run as administrator.
2. Run one of the following Commands:
   • To enable 32-bit mode:
     %windir%\system32\inetsrv\appcmd set apppool "SolarWinds Orion Application Pool" /enable32BitAppOnWin64:true

   • To disable 32-bit mode (switch back to 64-bit):

     %windir%\system32\inetsrv\appcmd set apppool "SolarWinds Orion Application Pool" /enable32BitAppOnWin64:false
3. Restart the Application Pool
   • %windir%\system32\inetsrv\appcmd recycle apppool "SolarWinds Orion Application Pool"