Error in re-building vignettes:
  ...
Loading required package: network
network: Classes for Relational Data
Version 1.15 created on 2019-04-01.
copyright (c) 2005, Carter T. Butts, University of California-Irvine
                    Mark S. Handcock, University of California -- Los Angeles
                    David R. Hunter, Penn State University
                    Martina Morris, University of Washington
                    Skye Bender-deMoll, University of Washington
 For citation information, type citation("network").
 Type help("network-package") to get started.


networkDynamic: version 0.10.0, created on 2019-04-04
Copyright (c) 2019, Carter T. Butts, University of California -- Irvine
                    Ayn Leslie-Cook, University of Washington
                    Pavel N. Krivitsky, University of Wollongong
                    Skye Bender-deMoll, University of Washington
                    with contributions from
                    Zack Almquist, University of California -- Irvine
                    David R. Hunter, Penn State University
                    Li Wang
                    Kirk Li, University of Washington
                    Steven M. Goodreau, University of Washington
                    Jeffrey Horner
                    Martina Morris, University of Washington
Based on "statnet" project software (statnet.org).
For license and citation information see statnet.org/attribution
or type citation("networkDynamic").

trying URL 'http://vlado.fmf.uni-lj.si/pub/networks/data/esna/Sampson.zip'
Warning in download.file("http://vlado.fmf.uni-lj.si/pub/networks/data/esna/Sampson.zip",  :
  InternetOpenUrl failed: 'Die Serververbindung konnte nicht hergestellt werden.'

Error: processing vignette 'networkDynamic.Rnw' failed with diagnostics:
 chunk 47 (label = download_paj) 
Error in download.file("http://vlado.fmf.uni-lj.si/pub/networks/data/esna/Sampson.zip",  : 
  cannot open URL 'http://vlado.fmf.uni-lj.si/pub/networks/data/esna/Sampson.zip'
Execution halted