Go to documentation repository
The ‘key file not found’ error appears in case if there is no ‘AxxonPSIM‘psim.sec’ license file in the root of the Axxon PSIM software installation directory (by default, C:\Program Files (x86)\Axxon PSIM\). Also, this error is going to appear if the license file has been renamed.
...
In the event of such error, put the ‘AxxonPSIM‘psim.sec’ file in the Axxon PSIM software installation directory. If the activation key file has been renamed, rename it as ‘AxxonPSIM‘psim.sec’. If you don’t have this file, you should apply to the AxxonSoft manager in order to acquire it.