Two of my external HFS+ drives changed permission after I did something wrong while my iMac (Sierra) was connected to an old MacPro2.1 (Snow Leopard) and I shared all the disks on network. So I lost write permissions to the drive (at least the root directory) unless I always provide a password. I can't simply move files within it, I can't delete any directory in root. The worst thing is applications like Final Cut or Davinci Resolve lost it's permissions too. I didn't regain write permissions even after checking the tab "Ignore ownership on this volume". Still it tells me "You can only read"