GIT pull failed: 'unable to unlink file: invalid argument'

New GIT user here, managing a Moodle course web site system on a Windows server. Trying to do my first Pull update of the core code (using TortoiseGit) and it's not working. Git is unable to unlink old versions of any the 200+ files to be updated because of an "invalid argument". I have no idea what that means. Here's what it looks like after I dismiss 210 error dialogs: [tortoisegit][1] [1]: https://i.sstatic.net/iHmIM.png I've rebooted the server and scoured the web for ideas, but I'm at a loss for what to try next. Any ideas would be *greatly* appreciated!