Often, SIMATIC Logon relies on Windows User Groups. Ensure your current Windows login is part of the "Siemens TIA Engineer" or "Logon Administrator" group on the local machine.
Open your terminal directory holding the file Unlock_and_converter_MMC_Image_S7.exe . Run the executable file. unlock s7300exe work
If you do not need the old code, you can perform a Memory Reset (MRES) by holding the physical switch on the CPU, which wipes the card and removes the password. Often, SIMATIC Logon relies on Windows User Groups