In my case, I had to power down the NAS and disconnect the power from the hard drive. First, I started the NAS, then I initiated the array. Afterward, I powered down the NAS again, reconnected the hard drive, and powered the NAS back up. I realized that I had discarded many hard drives before understanding that I could rebuild them myself. I would recommend that the Unraid team make this option more evident, perhaps by providing users with a checkbox when the same drive is entered but has a red X, allowing them the choice to rebuild it.