I just went to mobile documents and checked the "documents" file, but it's empty. Not sure why it's showing 2 documents or files in FAF that I can't get rid of. Mobile documents showed up under iCloud Drive so not even there. I probably don't have to worry about it, but it's nice to get all files of an app gone."Mobile Documents" means nothing to me.
When you select items in FAF, you ordinarily see a complete path to them at the bottom of the FAF pane. Seeing the paths to those two items may help.
Hmmm... I found this: "[Mobile Documents] is the local copy of your iCloud 'Documents & Data' stored on your Mac." It sounds like Day One placed that stuff expecting you to use it with your phone.
The solution looks like navigating to ~/Library/Mobile Documents and deleting the entire folder. It shouldn't cause you any problems, because you don't use iCloud.
