Sorry for the mess, the reason you see that the key is invalid is because there is a "space" after the first 4 digits, therefore, instead of having 4 digits in the last bulk, you will only have 3 digits.
Please remove the space after the first 4 digits from your TXT file and copy-paste again.
How it looks in the file:
BKNA- MALB-5555-5555-5555-MLOZ --> When copying this, you will get BKNA- MALB-5555-5555-5555-MLO
How it should look:
BKNA- MALB-5555-5555-5555-MLOZ --> it should work this way :)
Sorry for the inconvenience.