Hi,
Yes, I have a similar problem with strato for about 3 months now. The error message is not the same but it is probably a RapidWeaver problem as this occurs only since an upgrade.
I have resorted to exporting the site to a directory on my desktop and using “Yummy ftp Pro” to upload the content to a directory that I then swap names with the original. Of course a fix would be good but life is too short. ! Attached the ftp settings I use.