No method matching coeftype

Hello,
I apologize if my question is dumb in advance. Flowing is my code, when I run it, it returns
" no method matching coeftype(::Array{JuMP.GenericAffExpr{Float64,JuMP.Variable},1})" .I don’s really understand the error message. Could any one tells me what does it mean?

using JuMP
using Clp
using Ipopt
include("acopf_input.jl")
path = pwd()"/case.dat"
casefilename, refbus, loadscale, thermalLimitscale, extras, mvaBase = readconfig(path)
generators, generatorlist, buses, lines = readcase(casefilename, extras, loadscale, thermalLimitscale, mvaBase)
numbuses = length(buses)
numlines = length(lines)
numgenerators = length(generators)
vold=[1.05 0;1.06 -0.03;1.04 0.149;1.04 0.093;1.015 0.1685;1.0331 0.1534;1.025 0.149;1.045 0.073;1.009 0.156]
#i0 is branch current
iold=[1.5 -0.7;0.78 -0.38;-0.12 0.08;0.06 -0.43;-0.05 -0.35;-1.04 0.144;-1.58 0.52;0.54 -0.37;-0.71 0.33]
ibus_opt=[-1.5 0.7;-1.58 0.52;-0.06 0.43;0 0;0.9 -0.46;0 0;0.99 -0.500 ;0 0;1.25 -0.72]
pgold=zeros(Float64,numbuses)
maxitr=30
h = 1
vsqold= zeros(Float64,numbuses)
isqold= zeros(Float64,numlines)
μv=zeros(Float64,numbuses) #!
μi=zeros(Float64,numlines) #!
P_tay=zeros(Float64,numbuses)
Q_tay=zeros(Float64,numbuses)
P_bilinear = zeros(Float64, numbuses)
Q_bilinear = zeros(Float64, numbuses)
βr = zeros(Float64, numbuses)
βj = zeros(Float64, numbuses)
αr = zeros(Float64, numbuses)
αj = zeros(Float64, numbuses)
φpn = zeros(Float64, numbuses)
φqn = zeros(Float64, numbuses)
stepvr = zeros(Float64, numbuses)
stepvj = zeros(Float64, numbuses)
stepir = zeros(Float64, numlines)
stepij= zeros(Float64, numlines)
δp=ones(Float64,numbuses)
δq=ones(Float64,numbuses)
δp_tot=numbuses
δq_tot=numbuses
while((h<30)&&((maximum(δp)>1e-4)&&(maximum(δq)>1e-4))&&((δp_tot>5*1e-4)&&(δq_tot>5*1e-4)))
    function solve_taylor(thermalLimitscale, generators, buses, lines)
        numbuses = length(buses)
        numlines = length(lines)
        numgenerators = length(generators)
        m=Model(solver=IpoptSolver())
        @variable(m,ir[1:numbuses]) #real current injected at node
        @variable(m,ij[1:numbuses]) #immaginary current injected at node
        @variable(m,irij[1:numlines]) #real current flow from i to j
        @variable(m,ijij[1:numlines]) #immaginary current flow from i to j
        @variable(m, gp[1:numgenerators])#Active power generated at certain generator
        @variable(m, gq[1:numgenerators])#Reactive power generated
        @variable(m, vr[1:numbuses] >=0)#Bus voltage real part
        @variable(m, vj[1:numbuses])#Bus voltage imanginary part
        @variable(m,vsqnew[1:numbuses] >= 0)
        @variable(m,isqnew[1:numlines] >= 0)
        @variable(m,gp_tot[1:numbuses])
        @variable(m,gq_tot[1:numbuses])
        @objective(m, Min, sum{generators[i].pi1*gp[i]^2+generators[i].pi2*gp[i]+generators[i].pi3, i=1:numgenerators})
        for j = 1:numlines
            con=@constraint(m,irij[j] == lines[j].γ* vr[lines[j].head] -lines[j].β * vj[lines[j].head] - lines[j].γ* vj[lines[j].tail] + lines[j].β*vj[lines[j].tail] )
            con=@constraint(m,ijij[j] == lines[j].γ* vj[lines[j].head] + (lines[j].β-lines[j].b_charge/2) * vr[lines[j].head] - lines[j].γ* vj[lines[j].tail] -lines[j].β*vr[lines[j].tail] )
            isqold[j]=iold[j,1]^2 + iold[j,2]^2
            #con=@constraint(m,isqnew[j]==2*(iold[j,1])*irij[j]+2*(iold[j,2])*ijij[j]-isqold[j])
            if lines[j].Imax > 0
                @constraint(m,-lines[j].Imax <= (irij[j]) <= lines[j].Imax)
                @constraint(m,-lines[j].Imax <= (ijij[j]) <= lines[j].Imax)
            end
            #Infeasibility Handling for current flow from i to j
            if iold[j,1]^2 + iold[j,2]^2 > lines[j].Imax^2
                μi[j]=iold[j,2]/iold[j,1]
                iold[j,1]=sign(iold[j,1])*(lines[j].Imax^2/(1+μi[j]^2))^0.5
                iold[j,2]=sign(iold[j,2])*abs(μi[j] * iold[j,1])
                @constraint(m,iold[j,1]* irij[j] + iold[j,2] * ijij[j] <= lines[j].Imax^2)
            elseif iold[j,1]^2 + iold[j,2]^2 <= lines[j].Imax^2
                @constraint(m,2*(iold[j,1])*irij[j]+2*(iold[j,2])*ijij[j]-isqold[j] <= lines[j].Imax^2)
            end
            #Constraint Reduction
            #if (irijopt[h-1,j]^2+ijijopt[h-1,j]^2 >= r^2 * lines[j].Imax^2) | (irjiopt[h-1,j]^2+ijjiopt[h-1,j]^2 >= r^2 * lines[j].Imax^2)

        end


        for i = 1:numbuses

            vsqold[i]=(vold[i,1])^2+(vold[i,2])^2
            #@constraint(m,vsqnew[i]==2*(vold[i,1])*vr[i]+2*(vold[i,2])*vj[i]-vsqold[i])

            #current injected at bus

            @constraint(m,ir[i]== sum{irij[k], k in buses[i].outlist}-sum{irij[k], k in buses[i].inlist}+vr[i]*buses[i].Gs-vr[i]*buses[i].Bs)

            @constraint(m, ij[i]==sum{ijij[k], k in buses[i].outlist}-sum{ijij[k], k in buses[i].inlist}+vj[i]*buses[i].Gs-vj[i]*buses[i].Bs)

            @constraint(m,gp_tot[i]==sum{gp[k], k in buses[i].genids})
            @constraint(m,gq_tot[i]==sum{gq[k], k in buses[i].genids})

            #@constraint(m, sum{gp[k], k in buses[i].genids}-vold[i,1]*ir[i]-vold[i,2]*ij[i]-vr[i]*ibus_opt[i,1]-vj[i]*ibus_opt[i,2]+vold[i,1]*ibus_opt[i,1]+vold[i,2]*ibus_opt[i,2]==buses[i].Pd)

            #@constraint(m, sum{gq[k], k in buses[i].genids}-vold[i,2]*ir[i]+vold[i,1]*ij[i]-vj[i]*ibus_opt[i,1]+vr[i]*ibus_opt[i,2]+vold[i,2]*ibus_opt[i,1]-vold[i,1]*ibus_opt[i,2]==buses[i].Qd)

            @constraint(m, -buses[i].Vmax <= vr[i] <= buses[i].Vmax)
            @constraint(m, -buses[i].Vmax <= vj[i] <= buses[i].Vmax)

            #Infeasibility Handling
            if vold[i,1]^2 + vold[i,2]^2 > buses[i].Vmax^2
                μv[i]=vold[i,2]/vold[i,1]
                vold[i,1]=sign(vold[i,1]*(buses[i].Vmax^2/(1+μv[i]^2))^0.5)
                vold[i,2]=sign(vold[i,2])*abs(μv[i] * vold[i,1])
                @constraint(m,vold[i,1]* vr[i] + vold[i,2] * vj[i] <= buses[i].Vmax^2)
            elseif vold[i,1]^2 + vold[i,2]^2 <= buses[i].Vmax^2
                @constraint(m,buses[i].Vmin^2 <= 2*(vold[i,1])*vr[i]+2*(vold[i,2])*vj[i]-vsqold[i] <= buses[i].Vmax^2)

            end


            P_bilinear[i] = vold[i,1]*iold[i,1]+vold[i,2]*iold[i,2]+buses[i].Pd
            Q_bilinear[i] = vold[i,2]*iold[i,1]-vold[i,1]*iold[i,2]+buses[i].Qd

            φpn[i] = max(0.001, abs(P_tay[i]-P_bilinear[i])/min(P_tay[i],P_bilinear[i]))
            φqn[i] = max(0.001, abs(Q_tay[i]-Q_bilinear[i])/min(Q_tay[i],Q_bilinear[i]))

            βr[i] = -0.15 * log10(φqn[i]) + 1
            βj[i] = -0.15 * log10(φpn[i]) + 1

            αr[i] = 1/βr[i]
            αj[i] = 1/βj[i]

            stepvr[i] = αr[i] * abs(buses[i].Vmax)/h^βr[i]
            stepvj[i] = αj[i] * abs(buses[i].Vmax)/h^βj[i]

            δp[i] = abs(P_tay[i]-P_bilinear[i])/min(P_tay[i],P_bilinear[i])
            δq[i] = abs(Q_tay[i]-Q_bilinear[i])/min(Q_tay[i],Q_bilinear[i])

            δp_tot=sum{δp[i],i=1:numbuses}
            δq_tot=sum{δq[i],i=1:numbuses}

            @constraint(m,-stepvr[i] <= vr[i]-vold[i,1] <= stepvr[i])
            @constraint(m,-stepvj[i] <= vj[i]-vold[i,2] <= stepvj[i])





        end
        for i =1:numgenerators
            @constraint(m,0<=gp[i]<=generators[i].Pgmax)
            @constraint(m,-generators[i].Qgmax<=gq[i]<=generators[i].Qgmax)
        end
        solve(m)
        return getvalue(gp),getvalue(gq),getobjectivevalue(m),getvalue(vr),getvalue(vj),getvalue(ir),getvalue(ij),getvalue(irij),getvalue(ijij),getvalue(gp_tot),getvalue(gq_tot)
    end

    (gp_opt,gq_opt,obj,vr_opt,vj_opt,ir_opt,ij_opt,irij_opt,ijij_opt,gp_tot_opt,gq_tot_opt)=solve_taylor(thermalLimitscale, generators, buses, lines);
    println("**************************************************************************************")
    println("The optimal cost is ", obj,"The iteration is", h,"vr is",vr_opt,"vj is",vj_opt)
    println("**************************************************************************************")

    #=vropt[h,:]= vr_opt
    vjopt[h,:]= vj_opt
    iropt[h,:]= ir_opt
    ijopt[h,:]= ij_opt
    irijopt[h,:]= irij_opt
    ijijopt[h,:]= ijij_opt
=#
    vold=hcat(vr_opt,vj_opt)
    iold=hcat(irij_opt,ijij_opt)
    ibus_opt=hcat(ir_opt,ij_opt)
    P_tay=gp_tot_opt
    Q_tay=gq_tot_opt
    println(h)
    h=h+1

end