Can zUMIs be used for Smart-Seq3 on only one sample

[realzhang]

I've performed Smart-seq3 on only one type of cells (~hundreds of cells from FACS), so actually only one BC was used.
But when I ran zUMIs on the fastq files:

Error in uik(bccount$cellindex, bccount$cs/1000) : 
  Method is not applicable for such a small vector. Please give at least a 5 numbers vector
Calls: cellBC -> .cellBarcode_unknown -> .FindBCcut -> uik
Execution halted