File '<file>' targeting '<platform>' is not compatible with the project's target platform '<platform>'
This message is generated when the assembly is built to target a platform that is different from the TargetPlatform Property of the project. You can receive this message in the following cases:
If the project's TargetPlatform is x86, and the assembly targets x64 or Itanium.
If the project's TargetPlatform is x64, and the assembly targets Itanium.
If the Project's TargetPlatform is Itanium, and the assembly targets x64.
If your Setup project uses 64-bit DLL custom actions (regardless of the TargetPlatform you specified), this message is generated as a warning. Otherwise, this message is generated as an error. The resolution is the same for both cases, as described below.
To correct this error
Change the TargetPlatform property to be consistent with assemblies being installed, or change the assemblies being added to the project.