Why is it like this? What is broken? How can I test what is broken? We tried plugging it into the Windows laptop again, and my files and photos could be read!! But it still can't be read on Mac and has the flashing problem.

After running for 3-5 minutes, my mom came in and unplugged the external hard drive forcefully (I yelled at her for doing that). I clicked 'Start' and let it ran, but it didn't have a progress bar and just had a 'Cancel' button.

It says that it detected an error and had the option of automatically fixing it. I then plugged in my WD hard drive to a Windows laptop. I tried changing the Mac laptop, changing the USB cord, same problem. Ever since that my WD hard drive has the flashing problem and can't be mounted on my Mac. When I charged up my Mac again it says that the disk was not ejected properly. I was not actively reading or writing to the external hard drive, but it did have a list of directories open (no individual photo files, but just the directory names). The WD Passport Ultra was plugged into my MacBook on battery. I tried opening up Disk Utility on my Mac, but it just spins forever trying to mount the external hard drive. It can be read on a Windows laptop (after Windows automatically fixed an error). When I plug my WD Passport Ultra 4TB external hard drive WDBBKD0040BBK-0A (with 2TB of family photos) into my MacBook Pro it has fast flashing of light and can't be mounted. After more than an hour I came back and the drive showed up on my Mac again. I plugged in again into my MacBook and left it there.

My passport ultra for mac