Error(s) in re-building vignettes:
--- re-building 'simmer-01-introduction.Rmd' using rmarkdown
--- finished re-building 'simmer-01-introduction.Rmd'

--- re-building 'simmer-02-jss.Rmd' using rmarkdown
Loading required package: ggplot2

Attaching package: 'simmer.plot'

The following objects are masked from 'package:simmer':

    get_mon_arrivals, get_mon_attributes, get_mon_resources

Quitting from lines 615-626 (simmer-02-jss.Rmd) 
Error: processing vignette 'simmer-02-jss.Rmd' failed with diagnostics:
DLL 'dplyr' not found: maybe not installed for this architecture?
--- failed re-building 'simmer-02-jss.Rmd'

--- re-building 'simmer-03-trajectories.Rmd' using rmarkdown
--- finished re-building 'simmer-03-trajectories.Rmd'

--- re-building 'simmer-04-bank-1.Rmd' using rmarkdown
--- finished re-building 'simmer-04-bank-1.Rmd'

--- re-building 'simmer-04-bank-2.Rmd' using rmarkdown
Quitting from lines 669-698 (simmer-04-bank-2.Rmd) 
Error: processing vignette 'simmer-04-bank-2.Rmd' failed with diagnostics:
DLL 'dplyr' not found: maybe not installed for this architecture?
--- failed re-building 'simmer-04-bank-2.Rmd'

--- re-building 'simmer-05-simpy.Rmd' using rmarkdown
--- finished re-building 'simmer-05-simpy.Rmd'

--- re-building 'simmer-06-queueing.Rmd' using rmarkdown
Loading required package: ggplot2

Attaching package: 'simmer.plot'

The following objects are masked from 'package:simmer':

    get_mon_arrivals, get_mon_attributes, get_mon_resources

Quitting from lines 70-78 (simmer-06-queueing.Rmd) 
Error: processing vignette 'simmer-06-queueing.Rmd' failed with diagnostics:
DLL 'dplyr' not found: maybe not installed for this architecture?
--- failed re-building 'simmer-06-queueing.Rmd'

--- re-building 'simmer-07-ctmc.Rmd' using rmarkdown
Loading required package: ggplot2

Attaching package: 'simmer.plot'

The following objects are masked from 'package:simmer':

    get_mon_arrivals, get_mon_attributes, get_mon_resources

Quitting from lines 156-161 (simmer-07-ctmc.Rmd) 
Error: processing vignette 'simmer-07-ctmc.Rmd' failed with diagnostics:
DLL 'dplyr' not found: maybe not installed for this architecture?
--- failed re-building 'simmer-07-ctmc.Rmd'

--- re-building 'simmer-08-philosophers.Rmd' using rmarkdown
Loading required package: ggplot2

Attaching package: 'simmer.plot'

The following objects are masked from 'package:simmer':

    get_mon_arrivals, get_mon_attributes, get_mon_resources

--- finished re-building 'simmer-08-philosophers.Rmd'

--- re-building 'simmer-aa-5G.Rmd' using rmarkdown
--- finished re-building 'simmer-aa-5G.Rmd'

SUMMARY: processing the following files failed:
  'simmer-02-jss.Rmd' 'simmer-04-bank-2.Rmd' 'simmer-06-queueing.Rmd'
  'simmer-07-ctmc.Rmd'

Error: Vignette re-building failed.
Execution halted