Background: I am trying to upgrade a 15 year old project using BarTender to framework 4.8.

The problem shows up when I create a Setup project and try to compile it. This is the error that I am seeing.

ERROR: File 'Seagull.BarTender.Print.dll' targeting 'AMD64' is not compatible with the project's target platform 'x86'

I have checked everything that ChatGPT and Stack Overflow suggested. Build Configuration, project targets, framework. All set to x64.

Dependency Walker swears that all dlls and exes are 64 bit. I have removed all "Any CPU" conditions, leaving only x64 in my projects. I have created an absolutely bare-bones solution consisting of a Winform project and a library project. The library project references Seagull.BarTender.Print.dll, which I got from the 64 bit installation of BarTender from Seagull Scientific.

I have exhausted every avenue that I can find and still the Setup file seems to be insisting that my setup project's platform is x86.

Has anyone run into this problem and fixed it?