Error detected but matlab did not specify the type of error. pls help out

function y = conjunctivitis

test = -1;

tf=10;

delta = 0.001;

M = 50;

t = linspace(0,tf,M+1);

h = tf/M;

h2 = h/2;

Mh=0.639;

beta1=0.11;

beta2=0.112;

Nh=5000;

muh=0.469;

sigmah=0.123;

u1=.72;

delta1=0.213;

Mb=0.91;

Nb=7000;

beta3=.561;

beta4=.210;

mub=0.11;

H1=0.1;

H2=0.2;

H3=0.3;

M1=0.4;

M2=0.5;

M3=0.6;

M4=0.7;

x1=zeros(1,M+1);

x2=zeros(1,M+1);

x3=zeros(1,M+1);

x4=zeros(1,M+1);

x5=zeros(1,M+1);

x6=zeros(1,M+1);

c1 = zeros(1,M+1); c2 = zeros(1,M+1); c3 = zeros(1,M+1); c4 = zeros(1,M+1);

lambda1 = zeros(1,M+1);

lambda2 = zeros(1,M+1);

lambda3 = zeros(1,M+1);

lambda4 = zeros(1,M+1);

lambda5 = zeros(1,M+1);

lambda6 = zeros(1,M+1);

x1(1) = 20;

x2(1) = 20;

x3(1) = 20;

x4(1) = 20;

x5(1) = 5;

x6(1) = 10;

while(test < 0)

oldc1 = c1;

oldc2 = c2;

oldc3 = c3;

oldc4 = c4;

oldx1 = x1;

oldx2 = x2;

oldx3 = x3;

oldx4 = x4;

oldx5 = x5;

oldx6 = x6;

oldlambda1 = lambda1;

oldlambda2 = lambda2;

oldlambda3 = lambda3;

oldlambda4 = lambda4;

oldlambda5 = lambda5;

oldlambda6 = lambda6;

for i = 1:M

%for i = 1:M

m11 = Mh-((1-c1(i)).*beta1+(1-c2(i)).*beta2).*(x1(i).*x6(i))/(Nh)-muh.*x1(i)+sigmah.*c3(i).*x4(i);

m12 = ((1-c1(i)).*beta1.*x1(i).*x6(i))/(Nh)-muh.*x2(i)-(u1.*x2(i))/(1+x2(i));

m13 = ((1-c2(i)).*beta2.*x1(i).*x6(i))/(Nh)-(muh+delta1).*x3(i)-(u1.*x3(i))/(1+x3(i));

m14 = (u1.*x2(i))/(1+x2(i))+(u1.*x3(i))/(1+x3(i))-(muh+c3(i).*sigmah).*x4(i);

m15 = Mb.*Nb(1-c4(i))-(((1-c1(i)).*beta1.*x2(i)+(1-c2(i)).*beta2.*x3(i)).*x6(i))/Nb-c4(i).*mub.*x5(i);

m16 =(((1-c1(i)).*beta1.*x2(i)+(1-c2(i)).*beta2.*x3(i)).*x6(i))/Nb-c4(i).*mub.*x6(i);

m21 = Mh-((1-(0.5.*(c1(i)+c1(i+1))).*beta1+(1-(0.5.*(c2(i)+c2(i+1))).*beta2))).*(x1(i)+h2.*m11).*(x6(i)+h2.*m16)/(Nh)-muh.*x1(i)+sigmah.*c3(i).*x4(i);

m22 = ((1-(0.5.*(c1(i)+c2(i+1)).*beta1.*(x1(i)+h2.*m11).*(x6(i)+h2.*m16))))/((Nh)-muh.*(x2(i)+h2.*m12))-(u1.*(x2(i)+h2.*m12))/(1+(x2(i)+h2.*m12));

m23 = ((1-(0.5.*(c2(i)+c2(i+1)).*beta1.*(x1(i)+h2.*m11).*(x6(i)+h2.*m16))))/(Nh)-(muh+delta1).*(x3(i)+h2.*m13)-(u1.*(x3(i)+h2.*m13))/(1+(x3(i)+h2.*m13));

m24 = (u1.*(x2(i)+h2.*m12))/(1+(x2(i)+h2.*m12))+(u1.*(x3(i)+h2.*m13))/(1+(x3(i)+h2.*m13))-(muh+c3(i).*sigmah).*(x4(i)+h2.*m14);

m25 = Mb.*Nb(1-(0.5.*(c4(i)+c4(i+1))))-((1-(0.5.*(c1(i)+c1(i+1)))).*beta1.*(x2(i)+h2.*m12)+(1-c2(i)+c2(i+1)).*beta2.*(x3(i)+h2.*h13).*(x6(i)+h2.*m16))/Nb-c4(i).*mub.*x5(i);

m26 =(1-(0.5.*(c1(i)+c1(i+1))).*beta1.*(x2(i)+h2.*m12)+(1-(0.5.*(c2(i)+c2(i+1)).*beta2.*(x3(i)+h2.*m13).*(x6(i)+h2.*m16))))/Nb-((1-(0.5.*(c4(i)+c4(i+1)).*mub.*(x6(i)+h2.*h16))));

[Steven Lord]

What is the full and exact text (all the text displayed in red) of the error message you receive when you run this code? Don't summarize or paraphrase, just copy it verbatim from the Command Window into a comment.

[oluwatayo ogunmiloro]

@Steven Lord That is the error i ecountered below.

Error in conjunctivitis (line 89)

m25 =

Mb.*Nb(1-(0.5.*(c4(i)+c4(i+1))))-((1-(0.5.*(c1(i)+c1(i+1)))).*beta1.*(x2(i)+h2.*m12)+(1-c2(i)+c2(i+1)).*beta2.*(x3(i)+h2.*h13).*(x6(i)+h2.*m16))/Nb-c4(i).*mub.*x5(i);

>>

Answer 1

[Walter Roberson]

m25 = Mb.*Nb(1-(0.5.*(c4(i)+c4(i+1))))-((1-(0.5.*(c1(i)+c1(i+1)))).*beta1.*(x2(i)+h2.*m12)+(1-c2(i)+c2(i+1)).*beta2.*(x3(i)+h2.*h13).*(x6(i)+h2.*m16))/Nb-c4(i).*mub.*x5(i);

MATLAB does not have implied multiplication so Nb(expression) is a request to index the scalar Nb.