Question: system of PDE s to Solve

i have 12 second order non linear coupled partial differential equations (Euler-Lagrange Equations) in 12 variables {u1a(x1+l/2),u2a(x1+l/2),u3a(x1+l/2),theta1a(x1+l/2),theta2a(x1+l/2),theta3a(x1+l/2), u1p(x1,x2),u2p(x1,x2),u3p(x1,x2),theta1p(x1,x2),theta2p,theta3p}

also there are 17 lagrange multipliers in these equations which are also to be solved, using 17 constraints equations.

along with 48 boundary conditions. These have emerged out of variational formulations

u1a and others appear in the PDE as Du1a(x1+l/2) and so on.

Each of the equations is very large.

Rest of the constants in the problem are parametric nothing is numeric

I am using pdsolve([set of equations],[list of variable]) to solve.

but it is giving following error:

>

Error, (in pdsolve/sys) the input system cannot contain equations in the arbitrary parameters alone; found equation: E211
>

please help . How to proceed for solving of such a huge bundle of equations????

I have generated the Euler-Lagrange equations manually and not used the in-built method of doing so in Maple.

Kindly help.

thanks in advance.

regards