Platform: Windows Applies to: COMSOL Multiphysics® Versions: 6.1

Problem Description

COMSOL Multiphysics won't start on my computer, which uses a new Intel Xeon processor. I can see the splash screen, but the program doesn't go beyond that.


So far, this issue has been observed on Intel® Xeon® w3-2435, Intel® Xeon® w5-2445, Intel® Xeon® w7-2495X, Intel® Xeon® Gold 6426Y, and Intel® Xeon® Gold 6430 processors. However, it's possible that it might impact other processors as well.


There are two possible ways of solving this issue:

Adding a Switch to the Start Command

Add the following command switch to the COMSOL command:

-allocstack 4

In Windows, the simplest way to do this is to right-click the COMSOL shortcut and select Properties. In the Target edit field, add the switch above after comsol.exe. The target should look like this:

"C:\Program files\COMSOL\COMSOL61\Multiphysics\bin\win64\comsol.exe" -allocstack 4

Using a Permanent Command Switch

Follow these steps to resolve the issue:

  • Open Windows File Explorer and navigate to the following directory: C:\Program Files\COMSOL\COMSOL61\Multiphysics\bin\win64.
  • Locate the comsol.ini file and open it with a text editor.
  • Insert a new line in this file with the following content: -Dcs.allocstack=4.
  • Save the changes and close the text editor.
  • Try running COMSOL Multiphysics once more.

The allocstack command switch is not expected to affect the computational performance in any way.

Please note, if you're using a computer with these processors as a server for client-server computations, the same new line should also be added to the comsolmphserver.ini file.