Having PLCSIM V13, V14, and V15 on the same machine often leads to DLL hell. For a "better" setup, use the Siemens "Simulation Software Uninstaller" tool or manually clean out old versions via Windows Control Panel.
Ensure your TIA Portal project version matches the PLCSIM version. Compiling V15.1 code directly into a V15.1 simulation environment prevents firmware mismatch errors. simatic s7plcsim v151 download better
Access full diagnostic error logs on virtual hardware just like a physical CPU. Prerequisites and System Requirements Having PLCSIM V13, V14, and V15 on the