Good luck if you're dealing with Windows 10. I'm a Mac user but have two programs I depend on that run only on Windows, so I have to keep a Windows box around. At some point the thing decided I did not have authority to modify files in the Documents folder that Win10 creates, even though I operate as Administrator and am in fact the only authorized user (and have never personally set limited permissions on anything in that computer.) I fooled around with all the Permissions I could find and it didn't fix the problem. I gather there's some additional, higher level of security that Win10 also imposes, that's based on group authorizations or some such, but I could never figure out exactly what that was, how it fit on a single-user computer, or how to set it to let me write where I wanted to. I ended up creating a new "Documents" folder with a slightly different name, copied everything over to it (this computer has word processing, spreadsheet and email files from 25 years of prior Windows machines, in hundreds of sub- and sub-sub- folders in the Documents top folder) and now use that as the destination for all files.

So if the immediate problem is not camera-induced, and you can't find the correct Windows permission to fix it, maybe this is a solution - however inelegant.