re: We ran the update this morning (3/28/17) and experienced the same issue.
Was there any errors shown, if so, what were they? If there were none displayed, can you please look in the PHP error log to see what error was generated?
Within about an hour I am releasing another update, but, it is unlikely to address whatever the issue was. So I’ll need more to go on.
re: we are running on Linux
Most of the web is run using Linux, even if running IIS the process of logging into the site with FTP to delete the folder would be the same.
Previous version can always be found on this page… awe heck wp.org changed the plugins directory, again … I be darned if I can find the links to the previous versions now. Since you found it … where was it? Funny I have to ask :(