Dynamic Data Exchange and Excel
If you're working in Windows, and you find that Excel files won't open from Windows Explorer when you click on them (but will open just fine if you do a local open from inside Excel and browse to them) but instead get this error message:
You probably have a problem with your Dynamic Data Exchange setting. In Excel 2016 go to File . . . Options . . . Advanced tab and scroll down to the General section. Uncheck the box for 'Ignore other applications that use Dynamic Data Exchange (DDE)'. Dynamic Data Exchange controls how Windows applications interact with one other.
Alternatively if you are working with a lot of data in an Excel worksheet, it may function better if you check this off.