At times, the adjoint solver can struggle to get over the first iteration, and the AMG does not respond well. Defensive checks have been built-in to avoid divergence by looking at the AMG convergence history, and the code will not add garbage into the adjoint calculation if the AMG is seen to be failing. However, in cases showing the reported error message, these checks are too conservative. To work around this error message and allow the first iteration to continue, please type the following command into the TUI console window: (rpsetvar ‘adjoint/unusable-corrections-accepted? #t) The calculations should work as expected.