how to fix this?

> ClonalGeneUsagePlot(combined.freq, genes = c("IGLJ"))
Error in `combine_vars()`:
! Faceting variables must have at least one value.

> table(unlist(lapply(BCR_list, function(x) x$j_gene)))
IGLJ1 IGLJ2 IGLJ3 IGLJ7 
3741  7476  7390    48 