Failure in initial user-supplied objective function evaluation. FMINCON cannot continue.

I am try to run the following code

 A=zeros(n-1,n);
b=zeros(n-1,1);
Aeq=ones(1,n);
beq=1;
lb=zeros(n,1);
ub=ones(n,1);
x0=repmat(1/n,n,1);
fun=@(x)sum(abs(count-x));

where n is predefined and count is a vector of length n. But it gives the following error:

Error using - Matrix dimensions must agree.

Error in @(x)sum(abs(count-x(1:n)))

Error in fmincon (line 564) initVals.f = feval(funfcn{3},X,varargin{:});

Error in Training_ChiSquared_50 (line 92) x = fmincon(fun,x0,A,b,Aeq,beq,lb,ub);

Caused by: Failure in initial user-supplied objective function evaluation. FMINCON cannot continue.

Can anyone please help me to resolve the problem ?

[Torsten]

Where do you define "count" ? Is it predefined somewhere ?

The solution to your problem is very simple: x = count.

Best wishes

Torsten.