All Solutions

Singular Matrix

Solution Number: 1194 Applies to: COMSOL Multiphysics Versions: All versions

An error "Singular matrix" occurs. The system matrix (Jacobian matrix or stiffness matrix) is singular, so the solver cannot invert it. Usually this means that the system is underdetermined. Check that all equations ...


License Error

Solution Number: 1195 Applies to: COMSOL Multiphysics Versions: All versions

I receive a license error when installing, or launching, COMSOL Multiphysics, There are separate Knowledge Base entries for the most common error messages users experience. See the list under Related Issues below. If ...


'Command not found' or 'No such file or directory' error when starting the license manager on Linux

Solution Number: 1199 Versions: All versions

When I try to start the license manager for COMSOL 5.0, or later, on my Linux distribution I get an error message saying: ./lmgrd: Command not found. or ./lmgrd: No such file or directory The license manager ...


Solving time dependent models with inconsistent initial values

Solution Number: 1172 Versions: All versions

A common mistake when setting up transient models is to have initial conditions that are inconsistent with the loads and boundary conditions. This occurs most often when running transient fluid flow studies, but the ...


COMSOL Multiphysics crashes when trying to access the documentation

Solution Number: 1178 Versions: 5.4, 5.3a, 5.3, 5.2a

COMSOL Multiphysics crashes when I try to access the documentation on my Linux Machine. With the release of COMSOL Multiphysics 5.4, the documentation will automatically be opened in an external web browser if ...


Improving Convergence of Nonlinear Stationary Models

Solution Number: 103 Versions: All versions

Stationary (time-invariant) models with nonlinearities may converge very slowly. A nonlinearity can be introduced into the model either in the governing equation, or by making any of the material properties, loads, or ...


Error: Failed to Connect to Inventor LT

Solution Number: 1167 Versions: All versions

When I try to synchronize the geometry between COMSOL and Inventor LT, the error message Failed to connect to Inventor. Please make sure Inventor is running. is displayed. Inventor LT does not support third party ...


Using Symmetries in COMSOL Multiphysics

Solution Number: 1038 Versions: All versions

How do I take advantage of the symmetries in my COMSOL model? ##Using Symmetries to Reduce Model Size By using symmetries in a model you can reduce its size by one-half or more, making this an efficient tool for ...


Error: Failed to Connect to Solid Edge

Solution Number: 1160 Applies to: LiveLink for Solid Edge Versions: All versions

When I try to synchronize the geometry between COMSOL and Solid Edge, the error message Failed to connect to Solid Edge. Please make sure Solid Edge is running. is displayed, and the COMSOL Multiphysics tab in Solid ...


Error: Failed to Connect to Inventor

Solution Number: 1163 Versions: All versions

When I try to synchronize the geometry between COMSOL and Inventor, the error message Failed to connect to Inventor. Please make sure Inventor is running. is displayed. In addition, in the Inventor user interface, ...