System Error 998 While Loading LabVIEW DLL

Issue Details

• I created a DLL in LabVIEW to use it in Visual C++. When loading the DLL, LabVIEW reports System error 998. How can I troubleshoot this?
• I installed LabVIEW Run-Time Engine on the computer with Visual C++ and try to call a DLL. 
  The Visual C++ application compiles correctly, but it gives System Error 998 when linking the LabVIEW DLL. What is the problem?
• I have created a LabVIEW executable and have installed the correct version of LabVIEW Run-Time. When I run my application, I see the error below. How can I fix this?

Solution

For DLLs created in Visual C++

1. Call the LabVIEW DLL using the LoadLibrary and GetProcAddress to dynamically load the DLL and call the function.
2. Then, use the Visual C++ delayload feature as shown below, where sampleDLL.dll is the name of the LabVIEW DLL. Refer to [External] Linker support for delay-loaded DLLs for more information. Note: When statically linking with a DLL, the linker provides options to delay load the DLL until the program calls a function in that DLL.

For the LabVIEW Run-Time Engine DLL

1. Ensure that a compatible version of LabVIEW Run-Time has been installed.
   • Refer to LabVIEW and LabVIEW Run-Time Engine Compatibility for a compatibility chart.
2. If this error occurs on a deployment PC, verify whether the same error occurs on the development PC.
   • If the error is not present on the development PC, this signifies that there is a difference between the development and deployment PC.
   • Review the Build Specifications of your LabVIEW application and ensure that all required dependencies have been included.
3. Consider creating a LabVIEW Installer that includes your application as well as the required version of Run-Time.
   • Refer to the section titled Include the Run-Time Using a LabVIEW Installer in Install or Include a LabVIEW Runtime Engine.
4. If the PC is using anti-virus software, verify whether the error persists when the anti-virus is disabled.
   • It is possible that the anti-virus is preventing Windows from loading the necessary DLLs.
5. Check whether the error persists when running a different LabVIEW application.
   • This will identify whether the problem is with the application itself.
6. Check if the error occurs on other deployment PCs.
   • If other PCs can run the application without issues, this indicates that there is a software issue on the original deployment PC.
   • Create a MAX Report of the working and non-working deployment PCs to compare software sets, and ensure that both have the same versions of NI software installed.
7. The installed version of LabVIEW Run-Time may be corrupted. To mitigate this possibility, uninstall and reinstall LabVIEW Run-Time.
   • Instructions can be found in Uninstalling NI Software if I Cannot Use Add/Remove Programs.

Additional Information