markers fails in explore mode if we don't have any row names

[LTLA]

Probably true of analysis mode as well.

y <- round(abs(Matrix::rsparsematrix(20000, 100, density=0.05) * 10))
se <- SingleCellExperiment(list(counts=y))
colData(se)$cluster <- sample(5, ncol(se), replace=TRUE)
reducedDim(se, "UMAP") <- matrix(runif(ncol(y) * 2), ncol=2)
saveRDS(se, file="test.rds")

and then, when you try to pick a different cluster in the marker table:

[LTLA]

IMO we should handle this on the UI side, just populate the row data with some dummy names if nothing is received.