Subscript out of bounds error for run_viper with dorothea regulons in R

Question

I've got an error message when trying to do a upstream TF analysis using DoRothEA and Viper. Any suggestion would be helpful, thanks.

data(dorothea_mm, package = "dorothea")

regulons <- dorothea_mm %>%
  dplyr::filter(confidence %in% c("A", "B", "C"))

tf_activities_stat <- run_viper(resLFC_tb, regulons,
                         options =  list(minsize = 4,   
                         eset.filter = FALSE, cores = 1, verbose = FALSE, nes = TRUE))

Error message: Error in regulon[[i]] : subscript out of bounds