External drive mysteriously changed from NTFS to exFat and became 'Dirty'...?

Hello! I am new here. I have a few WD drives and they are great! But, and I KNOW it likely has something to do with the power going out and therefore the drive not being disconnected properly, but mysteriously I noticed when I suddenly could not delete folders on the drive any more. Also, when using diagnostic tools, the drive now shows up as exFat!?? WTH…?!

So, Windows Disc-check does not work. CMD line does not work and throws an error. I cannot now write to or delete from the drive. And, unfortunately, it is my PRIMARY media drive which has about 3 1/2 TB of data. Some is backed up to the cloud and some I COULD move I guess if I absolutely HAD to format the drive (and maybe change it BACK to NTFS… :smile:)

I have NO bloody idea what to do; I’ve never ever seen this happen before. Any suggestions would be lovely.

Thank you!

BTW, I am currently running a LONG test on the drive using the Lifeguard application. I don’t know if it will help or do anything. Interestingly, otherwise, on the SHORT and SMART tests, the drive looks just fine. But, Windows has it marked as ‘Dirty’ and I cannot use it. If necessary, will reformatting it actually SOLVE this??? I sure do NOT want to go through that if it won’t.