Hello, We are using a one-layer quasi-geostrophic model to find a steady linear solution. The code we are using is attached. It is very similar in structure to working code that we have used previously. However, when we try running it, we get an error, copied below. The issue seems to be occurring in a structure that the user would not normally be interacting with. If you could offer any advice, that would be very much appreciated. Thank you, Keegan UFL:WARNING Form has no parts with arity 2. Traceback (most recent call last): File "QG1L-interface-drag.py", line 83, in <module> soln0 = steadylinearQG2d(ZTrial, ZTest, Gwinds, bcs) File "QG1L-interface-drag.py", line 29, in steadylinearQG2d linear_problem = LinearVariationalProblem(lhs(G), rhs(G), soln, bcs=bcs) File "/Users/krcove/firedrake/src/firedrake/firedrake/variational_solver.py", line 255, in __init__ F = ufl.action(J, u) - L File "/Users/krcove/firedrake/src/ufl/ufl/formoperators.py", line 121, in action return compute_form_action(form, coefficient) File "/Users/krcove/firedrake/src/ufl/ufl/algorithms/formtransformations.py", line 416, in compute_form_action u = arguments[-1] IndexError: tuple index out of range _____________ Keegan Cove Undergraduate Research Intern Department of Applied Math University of Waterloo Student ID: 20513673 Email: krcove@edu.uwaterloo.ca Telephone: +1 519 888 4567 x32746