Look for the line containing the keyword KNOW_HOW_PROTECT near the top of the block definition. Delete this exact line.
Users can read and upload the program from the PLC, but cannot modify or write new blocks without a password. unlock s7-300 plc password
Some tools claim to "remove" the password but actually only suppress the block. When you upload the program, it appears unlocked in Step 7. However, if you download a new block, the password returns. You haven't fixed the root issue. Look for the line containing the keyword KNOW_HOW_PROTECT
What are you using? (Simatic Manager v5.x or TIA Portal?) Some tools claim to "remove" the password but
The entire PLC is locked. No access to the block folder or diagnostics is permitted without entering the correct password.
Whether you need to or if you can wipe the PLC clean
Release the switch, and within 3 seconds, press it down to again.