The objective function `Val{false}()` is not supported by JuMP

Hi, I am trying to build a NHL DFS lineup optimizer using code found at which needs updated for the current version of JuMP. I’m very new to Julia and JuMP but I’ve had some success working on it until I got stuck at the following error:

 [1] set_objective(::Model, ::MathOptInterface.OptimizationSense, ::Val{false}) at /home/greg/.julia/packages/JuMP/iGamg/src/objective.jl:101
 [2] one_lineup_Type_4(::DataFrame, ::DataFrame, ::Array{Int64,2}, ::Int64, ::Int64, ::Int64, ::Array{Int64,1}, ::Array{Int64,1}, ::Array{Int64,1}, ::Int64, ::LinearAlgebra.Adjoint{Int64,Array{Int64,1}}, ::Array{Any,1}, ::Array{Int64,2}, ::Int64, ::Array{Int64,1}) at /home/greg/.julia/packages/JuMP/iGamg/src/macros.jl:979
 [3] create_lineups(::Int64, ::Int64, ::String, ::String, ::typeof(one_lineup_Type_4), ::String) at /data/Projects/Sports/NHL/lineupoptimizer.jl:265
 [4] top-level scope at /data/Projects/Sports/NHL/lineupoptimizer.jl:332
 [5] include at ./boot.jl:328 [inlined]
 [6] include_relative(::Module, ::String) at ./loading.jl:1094
 [7] include(::Module, ::String) at ./Base.jl:31
 [8] include(::String) at ./client.jl:431
 [9] top-level scope at REPL[1]:1
in expression starting at /data/Projects/Sports/NHL/lineupoptimizer.jl:332

The objective function I’m using is:

@objective(m, Max, sum(skaters[i,:Projection]*skaters_lineup[i] for i=1:num_skaters) + sum(goalies[i,:Projection]*goalies_lineup[i] for i=1:num_goalies))

The full code is at and also has the csv files I was using for testing.

I believe there is something wrong with the objective function formula I am passing in but am not sure. Any help is appreciated. Please let me know what other information I need to include or if I made some other posting mistake. Thank you.

Aren’t num_skaters and num_goalies equal to zero ?
I can reproduce it with

julia> using JuMP

julia> model = Model()
A JuMP Model
Feasibility problem with:
Variables: 0
Model mode: AUTOMATIC
CachingOptimizer state: NO_OPTIMIZER
Solver name: No optimizer attached.

julia> @objective(model, Max, sum(1 for i in 1:0))
ERROR: The objective function `Val{false}()` is not supported by JuMP.
 [1] error(::String) at ./error.jl:33
 [2] set_objective(::Model, ::MathOptInterface.OptimizationSense, ::Val{false}) at /home/blegat/.julia/packages/JuMP/iGamg/src/objective.jl:101
 [3] top-level scope at /home/blegat/.julia/packages/JuMP/iGamg/src/macros.jl:979

I just reported the unhelpful error message in

Here is where I thought I was assigning num_skaters and num_goalies

    # Load information for skaters table
    skaters =

    # Load information for goalies table
    goalies =

    # Number of skaters
    num_skaters = size(skaters)[1]

    # Number of goalies
    num_goalies = size(goalies)[1]