If you create a download file which includes names or addresses containing diacritics (i.e. accents) then you may find that when you open the file in Excel that the diacritics are not properly displayed - however if you open the file in other programs - e.g. Notepad - then the diacritics are displayed properly.
On Windows
If you have a computer running on Windows you can resolve the issue if you:
Open the CSV file using Notepad.
Click File, then click Save As.
In the dialog window that appears, select ANSI from the Encoding field.
Click Save.
When you will open this new CSV file using Excel your accented characters should be displayed properly.
On a Mac
If you have a computer running on Mac, there are multiple options to try :
if you have access to a Windows computer follow the method using Notepad above, Excel on the Mac will then display the diacritics properly.
Use the Numbers application instead of Excel.
If the options above are not possible then the best you can do using Excel on a Mac:
Create a new spreadsheet.
Import the data from the downloaded file using the Data menu.
Select Get External Data, Import text file.
For the File origin setting select Unicode 7.
This will remove the accents from the characters.