Configure projects to target platforms - Visual Studio (Windows) | Microsoft Learn[^] An interesting/easy thing to try is building specifically for x86 and x64, testing both. It's a bit weird this isn't inverted. (x64 = AMD instruction sets, afaik - even on Intel chips) Aside that, I think strings being a bit of a special animal is likely playing into this heavily. Also, setting a .Tag to an object (instead of a string) is "weird" but that weirdness may be a figment of my imagination and that may be a perfectly normal thing to do.