A model file compressed with Apple's Archive Utility fails to upload.
When Archive Utility compresses a directory, it creates a directory named __MACOSX that includes files with more than one period in the file name. For security purposes, these files aren't permitted. Use a different application to compress the model file or exclude the __MACOSX directory when you compress the model file, and then upload the model file again.
Note: macOS hides the __MACOSX directory by default, so you might need to show hidden folders to view it.