Access Denied, fresh installs

I installed OSX High Sierra after wiping my MBP mid-2015. Immediately afterward I installed Win8.1 via Boot Camp. I downloaded and installed the trial for Paragon NTFS. In OSX I created a text (RTF) file, recorded some text, and saved it. I switched to Windows, attempted to edit and save the text file, and upon saving it reported the following error:
Access to <filepath:filename> was denied.

I read another thread on here that dealt with the same error, but it seemed he was dealing with an external drive, and something termed a 'Capsule', which I am unfamiliar with.

Thank you in advance for any help.