Error using sym>tomupad

Dear all,

Please, help me with this error:

Error using sym>tomupad (line 1268)

Unable to convert 'struct' to 'sym'.

Error in sym (line 220)

S.s = tomupad(x);

Error in sym/privResolveArgs (line 1005)

argout{k} = sym(arg);

Error in sym/vertcat (line 14)

args = privResolveArgs(varargin{:});

Error in FINSOL_NCC (line 47)

vv_t = [k_t;m_t;c_t;l_t;z_t;u_t;v_t];

I attached the code, but probabily the problem is from this part:

c_t        = solve(EQ(1),sym('c_t'));
EQ(2)       = subs(EQ(2),{'c_t'},{c_t});
EQ(3)       = subs(EQ(3),{'c_t'},{c_t});
m_t         = solve(EQ(2),sym('m_t'));
EQ(3)       = subs(EQ(3),{'m_t'},{m_t});
l_t         = solve(EQ(3),sym('l_t'));
m_t         = subs(m_t,{'l_t'},{l_t});
c_t        = subs(c_t,{'l_t','m_t'},{l_t,m_t});

[Walter Roberson]

The problem is not that part. Those lines do not occur in the file until vv_t has already failed.

The problem originates in one of the other files.