OmniServer OPC UA and Additional Client Modules Are Missing

If OPC UA, Wedge, Imubit, Database, or other client modules are missing from the OmniServer Clients tab, verify that the Microsoft Visual C++ v14 Redistributable for x86 is installed. OmniServer is a 32-bit application. The x64 redistributable does not satisfy its 32-bit runtime dependencies, even when OmniServer is installed on a 64-bit version of Windows Server. 

One or more of the following may occur:

• OPC UA is missing from the Clients tab.
• Wedge, Imubit, Database, or other client options are missing.
• The OmniServer service runs, but the optional client modules do not load.
• osrvua.dll, uastack.dll, or osrvwdge.dll is present in the installation folder but not loaded by OmniServer.
• The OPC UA endpoint is not listening on TCP port 27730.
• Reinstalling OmniServer does not resolve the issue.
• Removing the license or changing the license does not resolve the issue.
• Downgrading OmniServer does not resolve the issue.

The affected modules require the 32-bit Microsoft Visual C++ v14 runtime, including:

• MSVCP140.dll
• VCRUNTIME140.dll

The affected machines had the Visual C++ v14 x64 redistributable installed, but not the x86 package.

The x64 runtime cannot be loaded by 32-bit OmniServer modules. As a result, Windows cannot load the affected DLL dependency chain, and OmniServer does not display the associated client modules.

This is not caused by the OmniServer license.

Resolution

Install the latest supported Microsoft Visual C++ v14 Redistributable for x86.

Use Microsoft’s official download page:

https://learn.microsoft.com/en-us/cpp/windows/latest-supported-vc-redist/

Under Visual C++ v14 Redistributable, locate Latest supported redistributable version and select X86.

The downloaded file should be named: vc_redist.x86.exe

The latest supported v14 runtime is binary-compatible with applications built using supported Visual Studio 2015 and later v14 toolsets. The package architecture must match the application architecture. OmniServer requires x86 because it is a 32-bit application.

1. Download vc_redist.x86.exe from Microsoft.
2. Run the installer as an administrator.
3. Select Install, or Repair if the x86 package is already listed.
4. Restart the OmniServer by Software Toolbox service.
5. Close and reopen the OmniServer configuration application.
6. Check the Clients tab for OPC UA and the other missing modules.

A full server restart can be used if required by the customer’s change-control process.