App Store preventing me to reinstall Mac OS

My old MacPro A1286 was acting up so I wanted to wipe it clean and reinstall Mac OS. I followed the steps and signed out everywhere, leaned the Hard Drive via Disk Utility and now when I want to reinstall the Mac Os it asks me to sign in with my Apple ID which then says Error. So now I have a wiped HD and unable to install Mavericks OS because of this prompt. Anyone with helpful advice?