Error in .computeSumFactors: cells should have non-zero library sizes

Question

While trying to run the following code in R:

list_of_sce <- list()
# Looping though the UMI_count 'split_factor' columns at a time
split_factor = 500
for(i in seq(1,ncols, split_factor)) {
  num_loop = floor(i / split_factor) + 1
  idx = ncols
  if (i + split_factor < ncols) {
    idx = i + split_factor
  } 
sce <- SingleCellExperiment(list(counts=UMI_count[, i : idx]))
# Normalization of the dataset containing 
# heterogenous cell data (different cell types)
clusters <- quickCluster(sce)
sce <- computeSumFactors(sce, cluster=clusters)
list_of_sce[[num_loop]] <- sce
}

I am getting the error:

Error in .computeSumFactors(assay(x, i = assay.type), subset.row = 
subset.row,  : 
cells should have non-zero library sizes

There are warnings, so when I run warnings() command I see the following:

> warnings()
Warning messages:
1: In .computeSumFactors(assay(x, i = assay.type), subset.row = 
subset.row,  ... :
encountered negative size factor estimates
2: In .computeSumFactors(assay(x, i = assay.type), subset.row = 
subset.row,  ... :
encountered negative size factor estimates
3:...
...
39:....

I do not understand why is this happening, and how to debug it. Any suggestions would be greatly appreciated.