Hello, thanks for the reply. Maybe there's something wrong with itch's download server when you're downloading it the last time, as the nightly build should also contain an .exe
We did re-download all builds from the itch's download page to verify if it's working and it's currently working fine, both the stable and nightly build:
You can try re-downloading the app from itch.io download page; or if you're installing it through the itch.io desktop app, you can open the app page, click the gear icon on the lower right corner, followed by clicking 'Manage' on the popup window that showed up, and then click 'Re-install'.
Let us know if this is still happening. Thanks!
EDIT: For extra safety, you can delete the folder C:\Users\[yourusername]\AppData\Roaming\Mannequin to ensure the old installation is cleaned up before re-downloading the app.