Argument "env" is missing, no default qplot or ggplot R

I have a dataset with three columns for which I am trying to plot a pdf for the column id. This is what part of my data looks like.

        day          ID   count
        8754     48112050     1
        8975     48112050     3
        8327     61010046     2
        8346     61010046  3997
        8506     61010046     1
        8605     61010046     1

      

        
        
        
      

    

I am using qplot for this:

qplot(count, colour=factor(ID), data=df, geom="density")

      

        
        
        
      

    

or ggplot:

ggplot(df, aes(x=count, colour= ID))+geom_density()

      

        
        
        
      

    

but it doesn't display PDF for all ids. When I enter, I realize that the only ids missing from the plot generated by qplot or ggplot are IDs that have no more than 2 occurrences in my data. In this example ID: 48112050.

I am plotting density for this id only and it works.

         day          ID   count
        8754     48112050     1
        8975     48112050     3

      

        
        
        
      

    

However, when I restrict my df to just including that ID, or any ID with two occurrences, qplot or ggplot gives me the following error:

Error in exists(name, envir = env, mode = mode) : 
argument "env" is missing, with no default

      

        
        
        
      

    

Does this mean that qplot / ggplot requires at least 3 points to plot the density function?