Passolo doesn't localize XAML files. It follows the Microsoft LocBaml method that was described in the early days of WPF. See here https://learn.microsoft.com/en-us/dotnet/desktop/wpf/advanced/how-to-localize-an-application for more details.

So you can localize the WPF binaries as DLL or EXE, Passolo will extract the localizable data from the BAML Streams and will finally create satellite assemblies. An exception is the localization of WPF ResourceDictionaries that are stored in XAML/XML files.

Ah, thanks! I wasn't aware of that.

We have been localizing DLLs on this with Passolo for the last 20 years, but the developers would like to move away from that. We don't always get all languages done at the same time and it seems like outdated DLLs in individual languages tend to crash the application. They are trying to go a different route, I was hoping XAML would work. I think we found a solution using an XML export.