Possible Protection Is Enabled. Press Unprotect And Check Datasheet Page

The datasheet says:

MSP430 uses a JTAG lock key stored in flash. Pressing "Unprotect" in the programming tool typically performs a "mass erase via JTAG password bypass," then clears the lock. The chip is erased. The datasheet says: MSP430 uses a JTAG lock

This is the "Chip Kill" switch. If Level 2 is enabled, the debug interface is permanently severed. ROP prevents external programmers

The most common form of protection triggering this message is (often called RDP in STM32 microcontrollers, or Security Bit in PIC/AVR devices). When enabled, ROP prevents external programmers, debuggers (like JTAG or SWD), or bootloaders from reading the contents of the device's flash memory. debuggers (like JTAG or SWD)