You may want to reset SystemModeler’s licensing information if you used the incorrect activation information to activate your copy, or if you want to upgrade to the professional version. After removing the previous license information, SystemModeler will ask for a new activation key after the next restart.

SystemModeler stores its licensing information in a file called mathpass. Rename this mathpass file, for example to “mathpassold”, to render the previous license information inaccessible to SystemModeler.


By default, the mathpass file is located at:

  • C:\ProgramData\SystemModeler\mathpass
  • C:\Users\<user>\AppData\Roaming\SystemModeler\mathpass

where <user> is your username on the computer.

This file may be in a hidden folder on your computer. You may need to enable your account to see hidden files to navigate to the mathpass file.


On Mac, the mathpass file may be located at:

  • ~/.systemmodeler/mathpass

To navigate to this file, open the Finder application. Press Cmd + Shift + G to open a file search dialog and enter “~/.systemmodeler/mathpass”. Finder opens the hidden folder.


On Linux, the mathpass file may be located at:

  • ~/.systemmodeler/mathpass