Windows 10 as target system up to TwinCAT 3.1 Build 4022.2
For Windows 10 target systems the transferred files cannot be overwritten; they have to be renamed first.
Up to TwinCAT 3.1 Build 4022.2, the Rename Destination option must be enabled for this purpose in the TMC Editor deployment. In later versions this is done implicitly when the target system uses Windows 10 as operating system.