In a minority of models, you may notice that the solution speed has slowed significantly compared to Motion release 2022 R1 and earlier. This is due to a change in the default setting for the Error tolerance factor for NR residual option, from None in 2022 R1 to Use in 2022 R2 and later. In these cases, you can manually set the Error tolerance factor for NR residual option to None to achieve the same behavior as before.

The Use FDM Jacobian option in Mechanical Analysis Settings is not available when opening earlier version models in release 2024 R1 and later. A workaround for this is to expose the option by running the script below in the Mechanical Scripting window.

### When using multiple analyses, check the order of the Motion you wish to change
motionAnalysis = Model.Analyses[0] ### When motion is the first analysis

userObj = motionAnalysis.Children[1]

analysisSettings = DataModel.GetUserObjectById(userObj.ObjectId)
analysisSettings.Properties["SolverControls/SolverType/UseFDMJacobian"].Visible = True
analysisSettings.NotifyChange()