That would be because the checksum was not repaired, they could have moved the checksum notices to the top to highlight its existence more clearly but whatever, I've seen it now.
The whole using MSC thing to get the checksum is just unfeasable for the average user, thankfully it shows you the algo so i may just replicate it into a tool, seriously, fuck using that.
This is for reference material.
#CRCTABLE "./table/table.lst" // index  of the crc table = 0
CSUM == FFFF // Seed is 0xFFFF
CALL MEMO(64F4, 4, 0) //Overwrite position 0x64f4 in memory with 0x0000 <--- Nullify the old checksum
CSUM <= CRC16I(40, 64F7, 1021) // Compute checksum with poly 0x1021 from 0x40-0x64f7
CALL WRITE(1A, 2) // write 16 bytes to offset 0x1a
CALL WRITE(64F4, 4) //write 32 bytes to offset 0x64f4
CALL SHOW //Print checksum