Popping back to say that I managed to resolve this issue by downloading a .reg file from the Internet which allowed me to "Take Ownership" of the G drive.
I restarted the PC, copied all the required data from the G drive to a spare partition.
After formatting the G drive completely, I copied the data back from the spare partition on to the G drive.
All is now working well with no error messages.
I do have another issue so I will open a new discussion thread for that.