I'm analysis the Illumina 450k methylation data using Rnbeads.

I came across this error. I need help to rectify this error

The command which I've used :

>rnb.set<-rnb.run.analysis(dir.reports=report.dir, sample.sheet=sample.annotation,data.dir=idat.dir, data.type="infinium.idat.dir")

After 5 hours it shows the error like this.

Error:

2017-11-11 22:43:21    10.7    INFO             Mapping 3 traits to point colors and types
2017-11-11 22:44:02    10.7   ERROR             Could not create file. cannot popen '/usr/bin/which 'gs' 2>/dev/null', probable reason 'Cannot allocate memory'
Error in logger.error(em) :
  Could not create file. cannot popen '/usr/bin/which 'gs' 2>/dev/null', probable reason 'Cannot allocate memory'
In addition: There were 50 or more warnings (use warnings() to see the first 50)

Thanks in advance.