I decided to change the optimizer to CFSQP from IPOPT and it seems to have fixed the problem for slow, normal and fast gait (although fast gait also requires the use of the slow target).

<t>Hi,<br/> I am generating subject-specific models for OA subjects. During the CMC phase of the model, I have been getting an error that says:<br/> "WARN- small force range for peri_l (0.438496 to 0.440396)". This warning then causes the optimization to fail and CMC crashes. Any ideas on how I can ...