windows 10 the itunes library file cannot be saved. The required file cannot be found.

Hello.

When I start Itunes 12.7.1.14, a popup appears with "The iTunes Library file cannot be saved. The required file cannot be found." Am running Windows 10 fall update. and ios 11.1 (15B93). I can login to iTunes, however, I do not know if this pop up is an issue. I've done a google search, and have seen anything relevant. Would appreciate any help towards resolution. Thank you.