Hi!
This is caused by the folder path containing accented / non-ASCII characters, for example "Téléchargements".
I was able to reproduce the exact same error on my side — the model files are present, but the loader fails when the app is located in such a path.
Please try this:
Move the whole extracted Thaluna folder to a simple path such as: C:\Thaluna or D:\Apps\Thaluna\
Then run Thaluna.exe again from that folder.
This should fix the issue immediately.
I’ll also improve this behavior in a future update so the app handles this case more gracefully