rreformat.sh and stats.sh program in BBmap

Hello there, i am working with RNA seq data and have paired end reads. While running the reformat.sh command I am getting this out put:

Set INTERLEAVED to false
Exception in thread “main” java.lang.AssertionError: File 19213R-08-01_S16_L002_R1_001.fastq exists and overwrite=false

what does it mean?

Also while working with paired end reads and calculating their read information with stats.sh program, is there any way to get the out put of both R1 and R2 files simultaneously in one file?