There are a lot of users working in XPression using Excel files between multiple users and XPression DataLinq™ who are getting notifications that the file is already in use.
Microsoft changed the way they share Excel files, as they have more users working in the cloud with OneDrive or other file sharing applications. The way graphics people are sharing files, is based in the Legacy mode, which might not be so easy to figure out. This video shows users how to set up Legacy Sharing in Excel, and gets users back to working on a shared file the way they need to.