Symptom
Starting PTV Visum/PTV Vissim fails with an error message:
"The settings apply to all users on this computer. Your selection will thus not be saved. To permanently save the changes, a user with administrator rights needs to edit the configuration with the "PTV Visum License Manager' program."
Or:
"The buffer file for license data has an old format"
Resolution
1) Open a windows explorer window.
2) Remove this file (for example for Visum 2024):
%AppData%\PTV Vision\PTV Visum 2024\licenses.data
3) Remove this file if present (for example for Visum 2024, this file is only created if the license has been selected by an administrator):
C:\ProgramData\PTV Vision\PTV Visum 2024\licenses.data
4) Start PTV Visum/PTV Vissim and select the license once.