Came across an interesting Microsoft Excel feature. Usually when you open a spreadsheet and it is in use by another user you’ll get the popup asking to open read only or notify. However, I found a scenario where it wasn’t prompting and just opening the file as a new file. For example if the file is called a.xls it was opening as a1.xls. Then when the user went to save the file it would pop up the save as dialog box, causing mass confusion.

It turns out the read only prompt can be turned off and Excel will start defaulting to this behaviour. Do this to turn it back on:

On the Tools menu select Options, then Security, and then select Read-only recommended.