view->layouts->save current?
No, look at his screenshot. There is an
A-some-unknown-diacritic instead of an
i-acute in the pathname, so it fails to open.
I have no idea where that character comes from, though. The patch above replaces the mb_str macro with fn_str() because the documentation says "converts to the format the native filesystem expects". Very likely, it will change nothing at all because it is the same anyway, but it is worth a try.
The location of the home folder is queried from Windows and (along with a few fallback paths) fed to a wxPathList from which the final, fully-qualified filename is returned.
It is unlikely that Windows returns a bad path (even Windows should
really know its own paths), so I am afraid it might come from wxPathList. But having no Czech System here, there's no way I could verify that theory.