I have a user who is working in Excel spreadsheets. He is opening the spreadsheets from a network location that is on a Windows 2012 Server. If he leaves the documents open overnight when he comes in and tries to save them he gets an error stating the files are Read-only and cannot be saved. The spreadsheets are not opened by another user nor did the server reboot. Is this common for Excel? Is there a setting in Excel that would fix this issue.