Excel interprets CSV as SYLK

If the header of the first column of your CSV is "ID", Excel will complain when opening the file.

The file format and extension of 'file.csv' don't match. The file could be corrupted or unsafe. Unless you trust its source, don't open it. Do you want to open it anyway?

Excel has detected that 'file.csv' is a SYLK file, but cannot load it. Either the file has errors or it is not a SYLK file format. Click OK to try to open the file in a different format.

This is document at https://support.microsoft.com/en-us/kb/323626. The solution is to wrap "ID" in quotes.

While I acknowledge that this is a ridiculous Excel issue I believe it would be quite common to have ID as the first column header and a workaround could be provided in this module.