MATLAB: Error using symbol array in my system of ODEs

Question

syms L(t) [1 n];
syms M(t) [1 n];
syms massbal_tray [1 n];
massbal_tray(1) = diff(M(1),t) == L(2)-L(1);

I want to use the above code so I can create a system with n ODEs, but I need to treat the first equation differently. I plan to do the rest in a for loop. However I'm getting an error and can't isolate the problem:

Unable to perform assignment because the left and right sides have a different number of elements.

Error in sym/privsubsasgn (line 1151)

            L_tilde2 = builtin('subsasgn',L_tilde,struct('type','()','subs',{varargin}),R_tilde);

Error in sym/subsasgn (line 972)

        C = privsubsasgn(L,R,inds{:});

Error in msche_dist (line 28)

massbal_tray(1) = diff(M(1),t) ==
> L(2)-L(1);