Local Onedrive files won't open when away from Wifi

Question

Why can't I open a Onedrive file that is saved to my Surface harddrive when I am away from WiFi. I literally opened the file up while I was with WiFi, so when I travelled to the non-WiFi location, the file would be available, or updated, or not be corrupted, or not do whatever crazy thing it does when it can't connect. Sadly I forgot to plug it in so it had to restart and did an update. When I tried to re-open the file that is literally on my harddrive, it said "Excel cannot open the file because the file format or the file extension is not valid".

This is ridiculous, and not the only time it has happened. Even if my Onedrive sync is up to date, at times when I am away from WiFi, when trying to open a file I get the same report. To be safe, I have made a practice to open the files I need to ensure that they will be available when I am away from WiFi.

If the files are on my computer drive, why can't I open them?? Please give a better solution then me hoping it is going to work every time I go out.

nikolinode · Answer

The catch is in how OneDrive’s Files On-Demand works. Out of the box, OneDrive doesn’t automatically keep all files on your Surface; it only fetches them when needed. That’s why sometimes you see the “Excel cannot open” error offline — the file wasn’t fully cached.

Here’s how you can maybe make OneDrive behave like you want:

How to force OneDrive to always keep local copies in sync

Option 1: Disable Files On-Demand (everything always offline)

Right-click the OneDrive cloud icon in the system tray → Settings.
Go to Sync and backup.
Uncheck: Save space and download files as you use them.

Now every file in OneDrive is stored locally on your Surface.
When you’re online, changes sync up/down automatically.
When you’re offline, the local copy is always there and up to date (as of your last sync).

Downside: Uses more disk space, since your entire OneDrive stays on the Surface.

Option 2: Selectively keep folders always offline