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Correction: When the Mac came into being, NTFS did not exist. Apple introduced the Macintosh in January 1984 during the Super Bowl, National Football League's championship game of American football. NTFS was introduced as the filesystem along with Windows NT, the OS that gave the filesystem its name, in July 1993. Thus, the Mac is more than nine years older than NTFS.

Having said that, you have a known problem. NTFS is superior to FAT. However, it has a low tolerance for improper dismounts. Windows can automatically and nondestructively rebuild NTFS following an improper dismount. Third-party NTFS drivers available on the Mac have limited ability to graciously handle improperly dismounted drives.

My advice to you is to locate a Windows computer and plug your drive into it. If the Windows computer is able to mount the drive, then dismount it properly. It should then work fine.
 
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