Previously I was able to open an Excel file from my folder and an attachment from Outlook with the same name.  Now it says it cannot open files with the same name at the same time.  Is this a change?  Because I do not want to save multiple files just to do a comparison.

Hi Vronique M Godfrey,

I tested your issue in my own environment, first I created a TEST Excel file, and sent this file as an attachment in Outlook 2013 to myself. I got the same error >>Sorry, Excel can't open two workbooks with the same name at the same time<<.

For this error message, the answer is: calculation ambiguity with linked cells. If you had a cell ='[Book1.xlsx]Sheet1!$G$33 and you had two books named Book1 open, theres no way to tell which one you mean.

You can refer to this article to get more information:
https://blogs.office.com/2009/01/08/why-cant-i-open-two-files-with-the-same-name/

But I found if I opened the attachment in Reading Pane (as shown in the following figure) first.

Close the first attachment file, then opened the email as a separate Window, and opened the attachment file in separate Window again.

You will find the name of 'TEST' file change to TEST(2).xlsx, then you can open the file in local folder.

I think you can try this method as a workaround to help you solve this issue.

Hope it's helpful.

Regards,

Emi Zhang
TechNet Community Su