Dear all, I've implemented my boundary conditions weakly in my compressible stratified problem, but I get the following error now: How should I proceed to fix this? Will Traceback (most recent call last): File "compressible.py", line 181, in <module> solve(a == L, out) File "/home/cserv1_a/apps/install/firedrake/0.12.0/lib64/python2.7/site-packages/firedrake/solving.py", line 120, in solve _solve_varproblem(*args, **kwargs) File "/home/cserv1_a/apps/install/firedrake/0.12.0/lib64/python2.7/site-packages/firedrake/solving.py", line 145, in _solve_varproblem options_prefix=options_prefix) File "/home/cserv1_a/apps/install/firedrake/0.12.0/lib64/python2.7/site-packages/firedrake/variational_solver.py", line 232, in __init__ super(LinearVariationalSolver, self).__init__(*args, **kwargs) File "/home/cserv1_a/apps/install/firedrake/0.12.0/lib64/python2.7/site-packages/firedrake/variational_solver.py", line 118, in __init__ if ctx.is_mixed: File "/home/cserv1_a/apps/install/firedrake/0.12.0/lib64/python2.7/site-packages/firedrake/solving_utils.py", line 152, in is_mixed return self._jacs[-1]._M.sparsity.shape != (1, 1) File "/home/cserv1_a/apps/install/firedrake/0.12.0/lib64/python2.7/site-packages/firedrake/function.py", line 248, in __getattr__ return getattr(self._data, name) AttributeError: 'CoordinatelessFunction' object has no attribute '_M' Exception AttributeError: "'LinearVariationalSolver' object has no attribute '_parameters'" in <bound method LinearVariationalSolver.__del__ of <firedrake.variational_solver.LinearVariationalSolver object at 0x7fcc08180090>> ignored