Package check result: ERROR

Check: CRAN incoming feasibility, Result: NOTE
  Maintainer: ‘John Wambaugh <wambaugh.john@epa.gov>’
  
  Days since last update: 6

Check: examples, Result: ERROR
  Running examples in ‘httk-Ex.R’ failed
  The error most likely occurred in:
  
  > base::assign(".ptime", proc.time(), pos = "CheckExEnv")
  > ### Name: solve_full_pregnancy
  > ### Title: Solve_full_pregnancy
  > ### Aliases: solve_full_pregnancy
  > ### Keywords: Solve
  > 
  > ### ** Examples
  > 
  > 
  > ## No test: 
  > # dosing schedule of 1 mg/kg BW/day for 40 weeks
  > # return solution by hour
  > out <- solve_full_pregnancy(chem.name = "fipronil",  
  +                            daily.dose = 1, 
  +                            doses.per.day = 1,
  +                            time.course = seq(0, 40*7, 1/24))
  Solving for chemical: fipronil (DTXSID4034609)
  >                    
  >                                
  > # return solution in chemical amounts for fetal compartments + placenta
  > maternal_compts <- c('gutlumen', 'gut', 'liver', 'kidney', 'lung', 'ven', 'art', 
  + 'adipose','thyroid', 'rest')
  > 
  > fetal_compts <- c(maternal_compts[! maternal_compts %in% c('adipose', 'gutlumen') ], 
  + "brain")
  > 
  > amt.out <- solve_full_pregnancy(chem.name = "fipronil",  
  +                                daily.dose = 1, 
  +                                doses.per.day = 1,
  +                                time.course = seq(0, 40*7, 1), 
  +                                track.vars = c(paste0("Af", fetal_compts), "Aplacenta"))
  Solving for chemical: fipronil (DTXSID4034609)
  > 
  > # return solution in concentrations for fetal compartments + placenta 
  > conc.out <- solve_full_pregnancy(chem.name = "fipronil", 
  +                                 daily.dose = 1, 
  +                                 doses.per.day = 1,
  +                                 time.course = seq(0, 40*7, 1), 
  +                                 track.vars = c(paste0("Cf", fetal_compts), "Cplacenta"))
  Solving for chemical: fipronil (DTXSID4034609)
  > 
  > # plot solution based on output 
  > plt.out <- solve_full_pregnancy(chem.name = "genistein", 
  +                                 dose = 1, plt = TRUE)
  Solving for chemical: genistein (DTXSID5022308)
  
  Execution halted