Hi everyone. So I have an iMac (27-inch, Late 2009), 3.06 GHz Intel Core 2 Duo. I'm currently updated to OS X El Capitan 10.11.5. My internal hard drive recently failed and I replaced it with a Samsung 850 Evo 500GB SSD. After replacing the hard drive and reinstalling the OS everything was working fine. I have a 3TB Toshiba external HDD that I have been using for years. It was working fine after replacing the internal drive and also after updating to 10.11.5. After a few days I decided to change my Admin Username through system preferences > Users and groups > Advanced Options and changed "full name." After this change, I received an error that said my external HDD could not be opened because it was un readable by the computer. I can still see the EX. HDD in disk utility, but cannot see it in Finder. - I checked finder preferences and EX. Drives is checked - I tried unplugging the Ex HDD and reconnecting - I tried plugging ex drive into another mac and received the same issue - I tried "first aid" in disk utilities and received "operation complete" message It appears that when I changed the admin username it repartitioned my ex HDD. All of my content is still on the HDD and I would like to make it readable again without formatting. I downloaded a trial of Stellar Phoenix Data Recovery program, ran scan, and I can see my files, but I don't want to pay $100 for the software to recover the files if I don't have to. Does anyone have suggestions?