Office 365, notably Excel 2013, sometimes has a problem opening an XLS or XLSX file by double clicking, open with, or when launched via the Desktop App using View or Lock & Open. However if ¬†you open Excel first, then use File…Open and select a file in a local folder it will open correctly.

It’s a bug in Office that can often be resolved with an Office Quick Repair:

  • Go to Control Panel
  • Select Program and Features
  • Select Microsoft Office 365
  • Select Change
  • Select Quick Repair