Package check result: ERROR

Check: re-building of vignette outputs, Result: ERROR
  Error(s) in re-building vignettes:
    ...
  --- re-building ‘correlation.Rmd’ using rmarkdown
  --- finished re-building ‘correlation.Rmd’
  
  --- re-building ‘influencefunction.Rmd’ using rmarkdown
  
  Quitting from lines 139-146 [simulate] (influencefunction.Rmd)
  Error: processing vignette 'influencefunction.Rmd' failed with diagnostics:
  there is no package called 'mets'
  --- failed re-building ‘influencefunction.Rmd’
  
  --- re-building ‘nonlinear.Rmd’ using rmarkdown
  ** Processing: /home/hornik/tmp/CRAN_special_noSuggests/lava.Rcheck/vign_test/lava/vignettes/nonlinear_files/figure-html/figpred2-1.png
  576x384 pixels, 3x8 bits/pixel, RGB
  Input IDAT size = 17181 bytes
  Input file size = 17283 bytes
  
  Trying:
    zc = 9  zm = 8  zs = 0  f = 0		IDAT size = 12662
    zc = 9  zm = 8  zs = 1  f = 0
    zc = 1  zm = 8  zs = 2  f = 0
    zc = 9  zm = 8  zs = 3  f = 0
    zc = 9  zm = 8  zs = 0  f = 5
    zc = 9  zm = 8  zs = 1  f = 5
    zc = 1  zm = 8  zs = 2  f = 5
    zc = 9  zm = 8  zs = 3  f = 5
                                 
  Selecting parameters:
    zc = 9  zm = 8  zs = 0  f = 0		IDAT size = 12662
  
  Output IDAT size = 12662 bytes (4519 bytes decrease)
  Output file size = 12740 bytes (4543 bytes = 26.29% decrease)
  
  ** Processing: /home/hornik/tmp/CRAN_special_noSuggests/lava.Rcheck/vign_test/lava/vignettes/nonlinear_files/figure-html/multifit-1.png
  576x384 pixels, 3x8 bits/pixel, RGB
  Input IDAT size = 29285 bytes
  Input file size = 29399 bytes
  
  Trying:
    zc = 9  zm = 8  zs = 0  f = 0		IDAT size = 22462
    zc = 9  zm = 8  zs = 1  f = 0
    zc = 1  zm = 8  zs = 2  f = 0
    zc = 9  zm = 8  zs = 3  f = 0
    zc = 9  zm = 8  zs = 0  f = 5
    zc = 9  zm = 8  zs = 1  f = 5
    zc = 1  zm = 8  zs = 2  f = 5
    zc = 9  zm = 8  zs = 3  f = 5
                                 
  Selecting parameters:
    zc = 9  zm = 8  zs = 0  f = 0		IDAT size = 22462
  
  Output IDAT size = 22462 bytes (6823 bytes decrease)
  Output file size = 22540 bytes (6859 bytes = 23.33% decrease)
  
  --- finished re-building ‘nonlinear.Rmd’
  
  SUMMARY: processing the following file failed:
    ‘influencefunction.Rmd’
  
  Error: Vignette re-building failed.
  Execution halted