Running examples in ‘pencal-Ex.R’ failed
The error most likely occurred in:

> base::assign(".ptime", proc.time(), pos = "CheckExEnv")
> ### Name: summarize_lmms
> ### Title: Step 2 of PRC-LMM (computation of the predicted random effects)
> ### Aliases: summarize_lmms
> 
> ### ** Examples
> 
> # generate example data
> set.seed(1234)
> p = 4 # number of longitudinal predictors
> simdata = simulate_prclmm_data(n = 100, p = p, p.relev = 2, 
+              seed = 123, t.values = c(0, 0.2, 0.5, 1, 1.5, 2))
>              
> # specify options for cluster bootstrap optimism correction
> # procedure and for parallel computing 
> do.bootstrap = FALSE
> # IMPORTANT: set do.bootstrap = TRUE to compute the optimism correction!
> n.boots = ifelse(do.bootstrap, 100, 0)
> more.cores = FALSE
> # IMPORTANT: set more.cores = TRUE to parallelize and speed computations up!
> if (!more.cores) n.cores = 1
> if (more.cores) {
+    # identify number of available cores on your machine
+    n.cores = parallel::detectCores()
+    if (is.na(n.cores)) n.cores = 8
+ }
> 
> # step 1 of PRC-LMM: estimate the LMMs
> y.names = paste('marker', 1:p, sep = '')
> step1 = fit_lmms(y.names = y.names, 
+                  fixefs = ~ age, ranefs = ~ age | id, 
+                  long.data = simdata$long.data, 
+                  surv.data = simdata$surv.data,
+                  t.from.base = t.from.base,
+                  n.boots = n.boots, n.cores = n.cores)
Sorting long.data by subject id
Sorting surv.data by subject id
Preliminary step: remove measurements taken after event / censoring.
Removed: 0 measurements. Retained: 600 measurements.
This computation will be run without parallelization 
Estimating the LMMs on the original dataset...
...done
>                  
> # step 2 of PRC-LMM: compute the summaries 
> # of the longitudinal outcomes
> step2 = summarize_lmms(object = step1, n.cores = n.cores)
Error in serverSocket(port = port) : 
  creation of server socket failed: port 11456 cannot be opened
Calls: summarize_lmms -> <Anonymous> -> makePSOCKcluster -> serverSocket
Execution halted
Examples with CPU (user + system) or elapsed time > 5s
           user system elapsed
fit_prclmm 0.23  0.008   6.092