You probably made a mistake with the saving of the dds-file
You did something wrong with Hex Editing. (without knowing)
When you save the file to early in the hex editing (like just forgot to delete the last 4 but you saved already) and then you do delete them and save it again. it will be corrupted.
Or you do the crc fix twice with the same file it also will be corrupted.
Just restart from the beginning, you probably made a mistake without knowing. It happens to all of us