PopGenome R package

I have .vcf file of a type of plant and I have to calculate a divergence time for the same. I am following popGenome R Package. During execution I am facing such type of error in R

Error in readData("VCF", Format, gffpath ="GFF"): Put your filr/files in a folder!

Even though I have stored my file in a separate folders.

Can anyone describe what's going wrong with the program.

Thank you!

vcf_handle <- .Call("VCF_open", "8_pop_unified.vcf.gz") 
ind <- .Call("VCF_getSampleNames",vcf_handle) 
samplenames <- ind[1:10] 
Genome.class <- readVCF("8_pop_unified.vcf.gz",numcols = 10, tid = "1",
   from=1, to= 10, approx = FALSE, out = "", 
   parallel = FALSE, gffpath = FALSE) > 
Genome.class <- readData("8_pop_unified.vcf",gffpath = "8_pop_unified_gff")

 Error in readData("vcf", gffpath = "gff") : Put your file/files in a folder