Error in ggplot2 density plot: "Error: Must request at least one colour from a hue palette."

Question

Having installed tidyverse, I can't get the following to work....

ggplot(iris, aes(x = Sepal.Length, fill = Species) + geom_density(alpha = .3)

The error reads: "Error: Must request at least one colour from a hue palette."

Any ideas?

Answer 1

Just for the record and for future readers, I had this error related with the specific column (iris$Species in this example) containing only NAs.

This happened because some libraries did not work properly after sourcing my code, and therefore some tables didn't have the proper format.