I was following the Mixscape vignette when I encountered the following error:

object <- RunMixscape(
    object = object, 
    assay = "PRTB", 
    slot = "scale.data", 
    labels = "gene", 
    nt.class.name = "NT", 
    min.de.genes = 5, 
    iter.num = 10, 
    de.assay = "RNA", 
    verbose = T,
    prtb.type = "KO")

Error: Cannot find 'gene' in this Seurat object

The error is clear enough, but the question is why. Naturally there are genes in my dataset that are visible to other functions, so I assume 'gene' in this context refers to some kind of annotation present in the vignette example but not in my dataset.

I did try fetching all the gene names using rownames() and adding them again using AddMetaData(), but so far without success. All I get is a column with my label filled with <NA>...

Any advice much appreciated!