Exclusive | Labview Runtime Engine 61

One of the most frequent questions on NI Forums is: "Can I install LabVIEW Runtime 6.1 Exclusive alongside LabVIEW 2020 Runtime?"

Answer: No, not reliably.

The "Exclusive" designation means its installer overwrites certain system DLLs (lvrt.dll, lvrtmain.dll) in the System32 folder. Newer runtimes use side-by-side assemblies (WinSxS) but still register global COM objects. When the 6.1 installer runs, it reverts those COM registrations, breaking any modern LabVIEW app. Conversely, installing a 2020 runtime after 6.1 will cause the 6.1 executable to crash with a "missing export" error. labview runtime engine 61 exclusive

The only safe coexistence strategy:

You might encounter "LabVIEW Runtime Engine 6.1 Exclusive" in three scenarios: One of the most frequent questions on NI

The LabVIEW Runtime Engine 6.1 provides the libraries and support files required to run applications built with National Instruments’ LabVIEW 6.1. Because applications depend on a specific runtime version’s DLLs, using the exact runtime that matches the build environment ensures stable execution and predictable behavior.

Key points:

Migration recommendation: When feasible, rebuild and test applications with a supported, modern LabVIEW version and runtime to improve security, OS compatibility, and maintainability.

If you want, I can: provide a short installer checklist, draft a README for end users, or write an email informing a team about requiring LabVIEW Runtime Engine 6.1.