error([05/Jan/2018 09:57:05] "GET /assets/flash/ZeroClipboard.swf?noCache=1515117425200 HTTP/1.1" 404 2371)

ZeroClipboard is only used in Bootstrap's documentation to make the "Copy" buttons for the code samples work. Presumably you're including docs.min.js (or some other docs-specific JS) by mistake.