Replace a file in Documents & Files and there is no revision history of the actual file.
When I replace a file in the Documents & Files module and then publish it, there is a log of the revision history but only of the meta information . I however cannot access a previous version of the actual document file that was uploaded in an earlier revision.
There is also a style "sfItemPreviewOverlay" over the"open the file" button preventing me from opening the document. If I however remove this, I can download the file but it is always the latest version and not the historical one that was present with that earlier version.
I have tested this on a few implementations and it seems to be a consistent bug.
Please note that currently Sitefinity does not provide functionality to revert to a previous version of a document or file. There is a feature request lodged to implement it for the future releases. Here is the link to the feedback portal to track its progress and vote to increase its popularity: