Does anyone know a good way to get assistance on a Windows 8.1 problem that manifests itself with OneDrive? I've tried the official Microsoft support channels and wasted well over 10 hours on multiple chats and remote desktop sessions without any real help. I can find all over the web various indications of people having a problem similar to mine, but with no solution. It seems like it might be out of scope for this site, but since it does affect my SP3 in case someone here might have any ideas. If not, though, and someone can suggest a way to get help, that would be great. I have 3 machines I work with regularly: a home desktop machine (machine A), a work desktop machine (machine B), and my SP3 (machine C). All 3 machines run Windows 8.1. My work machine runs Windows Security Essentials and is joined to my work domain. I use OneDrive to keep my files synced among the machines. Here's the problem: When I create or edit an MS Office file (for example, an Excel file) on machine B and then try to open it on either of the other machines after OneDrive syncs the file, both machine A and machine C will report the file as corrupt. If I visit OneDrive online and try to edit the file in a browser, I can do so. If I manually download the file to one of the other machines, they can work with it just fine. I believe (and have read a lot online to tell me that others believe this) that, in fact, the OneDrive synced file is not truly corrupted but something in the Windows security mechanism is causing it to be reported as such because the file came through the Internet. Just like how sometimes when you open an Office file it says "this file came from Internet, do you want to open it?", instead of doing that, the file is instead being reported as corrupt. So, the scenario essentially is this: file is on the OneDrive cloud. If opened on the cloud via a browser app, it is fine. If explicitly downloaded, the desktop Office can edit it. If downloaded "behind the scenes" via a OneDrive sync, the file is reported as corrupt by Office. This problem only seems to occur with Office files, and only with those that are "touched" by my work machine. Essentially, this defeats my ability to truly work with files across all my machines. I think that this problem is being caused by some security setting, application, or other that I'm hoping can be configured or removed so as to make all this work. Not every OneDrive user experiences this, but there are tons of people out there who are and I've not yet found a real solution. I thought that I could address this by adjusting the Office Trust Center settings on the machines. No luck. I think this is something that has be addressed in Windows. I'm in the process now of going back to Dropbox to see if this problem occurs in Dropbox. This really seems like something a MS support export could help me fix, but I sure haven't experienced that.