Why is Capital D 'Display' variable within Plots package stopping me from pre-compiling?

struct PlotsDisplay <: Display end

This is line 9 in types.jl within the Plots package. I’ve tried removing the package, using the garbage cleaner ‘gc’, rebuilding it, using different versions. Every time I try to compile it am then met with a top-level error during pre-compiling, stating that the function ‘Display’ is not defined. This problem has only occurred in the last few hours and I am currently stuck. Any insight into exactly how the Plots package operates, especially within types.jl, and how that could mess up my code would be much appreciated. Will update this thread as I keep trying. Have a nice day!

What version of Plots and Julia are you on? That line should be struct PlotsDisplay <: AbstractDisplay end and has been for the last two years.