I encountered the following error using your code (GR version: 0.63.1):
SystemError: opening file "C:\\Users\\ytian\\AppData\\Local\\Temp\\jl_SbuQV4fEbT.svg": No such file or directory
Stacktrace:
[1] systemerror(p::String, errno::Int32; extrainfo::Nothing)
@ Base .\error.jl:168
[2] #systemerror#62
@ .\error.jl:167 [inlined]
[3] systemerror
@ .\error.jl:167 [inlined]
[4] open(fname::String; lock::Bool, read::Bool, write::Nothing, create::Nothing, truncate::Nothing, append::Nothing)
@ Base .\iostream.jl:293
[5] open(fname::String, mode::String; lock::Bool)
@ Base .\iostream.jl:355
[6] open
@ .\iostream.jl:355 [inlined]
[7] _readfile(path::String)
@ GR C:\Users\ytian\.julia\packages\GR\KPElO\src\GR.jl:3710
[8] show()
@ GR C:\Users\ytian\.julia\packages\GR\KPElO\src\GR.jl:3768
[9] plot_data(flag::Bool)
@ GR.jlgr C:\Users\ytian\.julia\packages\GR\KPElO\src\jlgr.jl:1553
[10] plot_data
@ C:\Users\ytian\.julia\packages\GR\KPElO\src\jlgr.jl:1198 [inlined]
[11] plot(args::Matrix{Float64}; kv::Base.Iterators.Pairs{Union{}, Union{}, Tuple{}, NamedTuple{(), Tuple{}}})
@ GR.jlgr C:\Users\ytian\.julia\packages\GR\KPElO\src\jlgr.jl:1763
[12] plot
@ C:\Users\ytian\.julia\packages\GR\KPElO\src\jlgr.jl:1755 [inlined]
[13] top-level scope
@ .\In[2]:4
[14] eval
@ .\boot.jl:360 [inlined]
[15] include_string(mapexpr::typeof(REPL.softscope), mod::Module, code::String, filename::String)
@ Base .\loading.jl:1116