This error is displayed when the target memory is not set to the RAM or the RAM cannot be read/written.
Confirm the following items:
Make sure the target memory is set to the RAM.
Make sure the target memory area is opened in the memory window and read/write is enabled in this area.
If read/write still cannot be performed, check the BSC register setting. If the target memory is set to the SDRAM, the SDRAM must be initialized before setting the software break.