How to unprotect netlist?

There is an option in the main menu Project->Nets->NetlistProtected (Uncheck this box )

When netlist is protected, it is impossible:

• delete a part if at least one pin is connected
• change the part number
• connect pin to netlist
• remove pin from netlist

Your should know that:

• Parts with just one pin can be added to the netlist by dragging connection, and can also be removed from the PCB, if desired.
• Footprint can be changed if the number of pins does not become less.