I have an external hard drive that I use all the time to store files and photos. Every time I connect, a window pops up asking how to use the hard drive, which I usually choose to “Decide Later.”
But the other day, I accidentally clicked another option, and now I can no longer save photos to the hard drive, and the system says, “Read Only.” Is there a way to restore the previous read-write state without deleting the data on the hard drive?
You can open Finder > Applications > Utilities > Disk Utility to check if your disk is formatted as NTFS. If it is NTFS, macOS can only read it by default but cannot write to it.
You can use iBoysoft NTFS for Mac, a trusted software available on the App Store. Simply download it, and your NTFS drive will be mounted in read-write mode on your Mac. Download iBoysoft Data Recovery for Mac and have a try.
You can read this article to get more detailed information：[Fixed] Unable to Copy Files from Mac to External Hard Drive