This note is just to inform that the component currently have an issue when managing the cache.
The cache validation is using the filename and filetype to retrive the component from the cache, but if your applications handles documents with the same name but different binary content, you will only get to display the first document previewed.
This can be easily changed. Modify the aggregate on the GetFileCache action, to get the record by guid and change the guid generation on the WebPreviewer block. The guid generation that can be used is the GenerateSaltedMD5Hash function from the PlatformPasswordUtils extension.