I just registered and I believe set up my passport on my Mac. When I try to move my itunes library to it I get the message unable to modify my passport. I ran the check for it being set up properly.
Welcome to the Community.
Did you format/partition your hard drive? This is required for NTFS Passports before you can use them in Mac-based systems. Is it able to accept files in your Desktop?
thank you for your response. I believe I did! i downloaded the driver, accpeted terms etc, and was to the place where it has three options to check the driver. I didnot do the thrid one as it said it could take hours but I completed the first one and it indicated it was fine… I will try it again. It will not take documents either 
I went back and “replaced” the already installed driver and security apps. completed the smart status, and quick drive test. Both are fine… I apologize for not having correct language. I just wanted to drag my music to a hard drive
SO… I think I formatted it? 
Formatting the hard drive is not done by means of the WD Apps, but rather through the built-in Disk Utility app:
