Problem Description

After installing Update 1 for COMSOL Multiphysics 6.1, I receive an unexpected error when solving a transient study with the Magnetic and Electric Fields and Electrical Circuit interfaces.

The log file that I access from the error message mentions that "There is already a property 'hybridization' in 'Preconditioner Settings'."


The error appears for this combination of features:

  • The Magnetic and Electric Fields interface.
  • The Electrical Circuit interface.
  • A standard coupling between the two, through External I vs. U, External U vs. I, or External I-terminal.
  • A Time Dependent study step.

The error is triggered when the default solver configuration is being generated. The generation of the solver configuration is normally initiated when you compute the study.

There are currently three suggested solutions.

Download and Install the Hotfix

This issue has been fixed in a hotfix for COMSOL® software version 6.1 update 1. Go to the Product Updates page and download the hotfix.

Solutions Without the Hotfix

If you are prevented from installing the hotfix for some reason, try one of the following two solutions.

1. Generate the Default Solver with the Electric Circuits Interface Disabled

  1. Disable the Electrical Circuit interface in the Model Builder tree.
  2. Right-click the Study and select Show the default solver from the context menu.
  3. Enable the Electrical Circuit interface again.
  4. Select the Solution 1 node under Solver Configurations and click Compute.

In the last step, it is necessary to compute from the Solution node and not from the Study node. If you compute from the study node, this will trigger the default solver configuration to be reset, resulting in the error again. An alternative is to make the solver configuration into a custom solver by modifying it in some way, for example by tuning the time stepping or scaling the dependent variables. A custom solver will not be reset automatically.

2. Use a Manual Coupling

Don't use the standard couplings, but use a manual coupling: The currents or voltages from the coil or terminals can be fed into the circuit manually, and vice versa. You can learn more about Defining Multiphysics Models Manually with User-Defined Couplings in the COMSOL Learning Center.