Solution
If the custom user/operator interface is built using LabVIEW, then there will be a LabVIEW ini token that enables/disables authentication for DCOM, which enables the application to remote connect as guest without authentication. OLE and DCOM security got improved in Windows 10 vs Windows 7, so the DCOM security would affect remote sequence access from a LabVIEW custom interface. TestStand and its custom interfaces (named TestExec.exe) are all registered with the OS, so they have DCOM authentication. This is an extra step needed for LabVIEW built OIs.
- Open the custom interface ini file, stored in the same location as the custom interface .exe
- Add the line: ole.AuthnLevel=1
- Save and close