Drive not working after i deferred


I wanted to encrypt my external drive and so I downloaded VeraCrypt, I followed all the instructions and extracted the files to the drive and when the encryption process started I saw that it would take 24 hours, time which I did not have at the moment, so decided to defer it. I then proceeded to unmounts the drive, and when I put the drive back, the drive does not want to work and says that it can't even run a security scan because the drive needs to be formatted ( and I don't have back ups of the stuff on the drive). Please help, what do I do?????