CreateProcessW failed with return code: 193

[lucas-ng-acs-com-hk]

Question

BA - .NET Core 8.0
WiX toolset - 6.0.2

I want to create a bundle with customized UI(C#).
I already check the mbanative.dll is x64 except the WixToolset.BootstrapperApplicationApi.dll is x86.
Attach full source code.

Error:
[5E70:2960][2025-12-23T11:27:21]e000: Error 0x800700c1: CreateProcessW failed with return code: 193
[5E70:2960][2025-12-23T11:27:21]e000: Error 0x800700c1: Failed to launch bootstrapper application process: "C:\Users\lucasng\AppData\Local\Temp{9E65A222-147C-4A5F-9F63-A9EA99FCA21F}.ba\mbanative.dll" -burn.ba.apiver 569705357157400576 -burn.ba.pipe BurnPipe.{5A150FDA-5015-4A20-8A3B-3C10001B3601} {E95001FE-4C52-4F02-9CD3-206387993E4C}
[5E70:2960][2025-12-23T11:27:21]e000: Error 0x800700c1: Failed to create bootstrapper application process: C:\Users\lucasng\AppData\Local\Temp{9E65A222-147C-4A5F-9F63-A9EA99FCA21F}.ba\mbanative.dll
[5E70:2960][2025-12-23T11:27:21]e000: Error 0x800700c1: Failed to start bootstrapper application.

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[robmen]

It is not possible to ::CreateProcess() a DLL. This comment points to your problem <!-- Remove BootstrapperApplicationRef. Use BootstrapperApplication directly. -->. That doesn't make sense.

[robmen]

@lucas-ng-acs-com-hk You've edited this question several times so I'm not sure where you are at with it now. If you solved the problem, great. If not, then I think you'll need to debug to see if your .exe. These instructions may be helpful. If that dialog box doesn't display, then your .exe isn't able to start, which suggests that you're missing files required by your .exe in your BootstrapperApplication.