Package check result: ERROR

Check: CRAN incoming feasibility, Result: NOTE
  Maintainer: ‘Juan Alberto Molina-Valero <jamolinavalero@gmail.com>’
  
  Found the following (possibly) invalid URLs:
    URL: https://adaptbrdy.czu.cz/en
      From: README.md
      Status: Error
      Message: SSL peer certificate or SSH remote key was not OK [adaptbrdy.czu.cz]: server verification failed: certificate signer not trusted. (CAfile: /etc/ssl/certs/ca-certificates.crt CRLfile: none)
    URL: https://www.czu.cz/en
      From: README.md
      Status: Error
      Message: SSL peer certificate or SSH remote key was not OK [www.czu.cz]: server verification failed: certificate signer not trusted. (CAfile: /etc/ssl/certs/ca-certificates.crt CRLfile: none)

Check: examples, Result: ERROR
  Running examples in ‘FORTLS-Ex.R’ failed
  The error most likely occurred in:
  
  > base::assign(".ptime", proc.time(), pos = "CheckExEnv")
  > ### Name: tree.detection.multi.scan
  > ### Title: Tree-Level Variables Estimation
  > ### Aliases: tree.detection.multi.scan
  > 
  > ### ** Examples
  > 
  > 
  > ## No test: 
  > 
  > # Establishment of working directories (optional)
  > # By default here we propose the current working directory of the R process
  > 
  > dir.data <- getwd()
  > dir.result <- getwd()
  > 
  > 
  > # Loading example data of TLS multi-scan approach point cloud (LAZ file) to dir.data
  > 
  > download.file(
  + "www.dropbox.com/scl/fi/es5pfj87wj0g6y8414dpo/PiceaAbies.laz?rlkey=ayt21mbndc6i6fyiz2e7z6oap&dl=1",
  +               destfile = file.path(dir.data, "PiceaAbies.laz"),
  +               mode = "wb")
  trying URL 'www.dropbox.com/scl/fi/es5pfj87wj0g6y8414dpo/PiceaAbies.laz?rlkey=ayt21mbndc6i6fyiz2e7z6oap&dl=1'
  Content type 'application/binary' length 12898220 bytes (12.3 MB)
  ==================================================
  downloaded 12.3 MB
  
  > 
  > # Normalizing the whole point cloud data without considering arguments
  > 
  > pcd <- normalize(las = "PiceaAbies.laz",
  + 
  +                  id = "PiceaAbies",
  + 
  +                  scan.approach = "multi",
  + 
  +                  voxel_size = 0.01,
  + 
  +                  dir.data = dir.data, dir.result = dir.result)
  
                                                                                  
  /home/hornik/tmp/CRAN_special_donttest/FORTLS.Rcheck/FORTLS/python/voxel_grid_downsampling.py:7: RuntimeWarning: invalid value encountered in cast
    voxel_coord = tuple(np.floor(point / voxel_size).astype(int))
  > 
  > 
  > # Tree detection without considering arguments
  > 
  > tree.tls <- tree.detection.multi.scan(data = pcd,
  + 
  +                                       tls.precision = 0.05,
  + 
  +                                       slice = 0.2,
  + 
  +                                       dir.result = dir.result)
  Application of Statistical Outlier Removal (SOR) to the entire point cloud
  Retention of points with high verticality values
  Detection of tree stem axes
  Computing sections
  Error in .check_ncores(length(names)) : 31 simultaneous processes spawned
  Calls: tree.detection.multi.scan -> <Anonymous> -> makePSOCKcluster -> .check_ncores
  Execution halted

Check: for non-standard things in the check directory, Result: NOTE
  Found the following files/directories:
    ‘1.txt’ ‘2.txt’ ‘PiceaAbies.laz’ ‘PiceaAbies.txt’ ‘PinusRadiata.laz’
    ‘PinusRadiata.txt’ ‘RB.G.angle.count.html’ ‘RB.G.fixed.area.html’
    ‘RB.G.k.tree.html’ ‘RB.N.angle.count.html’ ‘RB.N.fixed.area.html’
    ‘RB.N.k.tree.html’ ‘RB.V.angle.count.html’ ‘RB.angle.count.csv’
    ‘RB.d.angle.count.html’ ‘RB.d.fixed.area.html’ ‘RB.d.k.tree.html’
    ‘RB.fixed.area.csv’ ‘RB.h.angle.count.html’ ‘RB.h.fixed.area.html’
    ‘RB.h.k.tree.html’ ‘RB.k.tree.csv’
    ‘metrics.variables.angle.count.plot.csv’
    ‘metrics.variables.fixed.area.plot.csv’
    ‘metrics.variables.k.tree.plot.csv’
    ‘opt.correlations.angle.count.pearson.html’
    ‘opt.correlations.angle.count.spearman.html’
    ‘opt.correlations.fixed.area.pearson.html’
    ‘opt.correlations.fixed.area.spearman.html’
    ‘opt.correlations.k.tree.pearson.html’
    ‘opt.correlations.k.tree.spearman.html’
    ‘simulations.angle.count.plot.csv’ ‘simulations.fixed.area.plot.csv’
    ‘simulations.k.tree.plot.csv’