Upload web documents to the local plone 5 server

Hello to the community,
I created a small site for testing outside of plone 5.
I used the Wysiwig BlueGriffon editor (I could have used TinyMCE).
I am trying to transfer the web documents (HTML files, images, pdf, css etc) in a folder to the plone 5.1.6 server also installed on my local computer under Windows 10, successively by WebDav then by FTP, but the result is surprising because on arrival, the files are truncated or more exactly the files display 0 kb.
What did I miss to get this result?
What precautions should I take to avoid this malfunction?
In advance, thank you for your insight.

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