Issue with using foreach - r

Question

I have a question regarding doing parallel simulation using foreach and I really appreciate to your help in advance as I have spent hours and hours and I keep getting errors.
I'm using foreach() for a simulation study where in each iteration I run a function that that function itself has some "regular" loops. When I run it sequentially, it works perfectly fine. On a linux server, when I run it using foreach in parallel inside R, it works fine but as soon as I run it in the batch mode using "nohup R CMD BATCH" command, it starts returning errors. I set the seed numbers manually for each simulation and it means that regardless of running them parallel inside R, parallel in the batch mode, and sequential inside R, my codes basically are run on the same simulated data so that if one way does not produce any error, others should not lead to error either but strangely, it's not the case. Has anyone had the same challenge?
I've spent hours and hours, putting exception handling but nothing happened.
Here is my code:
dataSim <- function(seedNum, n, mi, beta0FE, beta1, beta0RE){
# Setting the seed number:
set.seed(seedNum)
# Generating covariates:
x <- rnorm(n, mean = 0, sd = 1)
# Generating Y:
data <- data.frame(id = rep(1:n, each = mi), x = rep(x, each = mi),
beta0_RE = rep(beta0RE, each = mi))
etaTmp <- data$beta0_RE + beta0FE + beta1*data$x
piTmp <- exp(etaTmp)/(1 + exp(etaTmp))
data$Y <- sapply(piTmp, rbinom, n = 1, size = 1)
return(data)
}
# Data Simulation Parameters:
n <- 100
mi <- 30
beta0FE <- 0.3
beta1 <- 1
beta0RE <- rnorm(n, 0, 1)
# Simulation Parameters:
nSim <- 10000
nIter <- 4000
LME_Freq_Fun <- function(data){
fit.LME <- try(glmmPQL(Y ~ x, random = ~ 1 | id,
family = binomial, data = data))
print(class(fit.LME)[1])
if (class(fit.LME)[1] == "try-error"){
return(list(coef.FE.LME = rep(NA, 3),
coef.RE.LME = rep(NA, n)))
}else{
return(list(coef.FE.LME = fit.LME$coefficients$fixed,
coef.RE.LME = fit.LME$coefficients$random$id))
}
}
LME_Freq_RSLT <- foreach (i = 1:nSim) %dopar%{
print(paste("i=", i))
print("-------")
data <- dataSim(i, n, mi, beta0FE, beta1, beta0RE)
LME_Freq_Fun(data)
}
# Extracting elements from foreach:
Coef.Fixed.LME <- t(sapply(1:nSim ,function (i)
return(LME_Freq_RSLT[[i]][[1]] )))
Coef.Rand.LME <- t(sapply(1:nSim ,function (i)
return(LME_Freq_RSLT[[i]][[2]] )))
With no "try", I keep getting:
task 3527 failed - "$ operator is invalid for atomic vectors"
With try, my Coef.Fixed.LME becomes very strange with all elements "numeric.2" !