Excel error "cannot open file because the file format or file extension is not valid."

Question

I am trying to open an xlsx file (I have windows 7) and an error message "cannot open file because the file format or file extension is not valid." I have tried renaming without the x, and also opening in a different version of excel, but the programme will not let me. Any ideas? I'd really appreciate any help!

Answer 1

AndiWhitley, you may also want to check to see if your issue might be malware related, http://blogs.technet.com/b/the_microsoft_excel_support_team_blog/archive/2013/09/07/quot-cannot-open-the-file-because-the-file-format-or-extension-is-invalid-quot-opening-office-files.aspx

Answer 2

Hello all.

I also have this same problem... I am using an workbook with a macro where the workbook gets 'saved as'.

That all works fine. But, as soon as I close the created workbook and try to re-open it, Excel comes up with this message. 

I figured there might have been a problem with the extension (.xlsx) used in the macro code, but that doesn't change anything. 

• I downloaded the Microsoft Security Scanner as suggested on http://blogs.technet.com/b/the\_microsoft\_excel\_support\_team\_blog/archive/2013/09/07/quot-cannot-open-the-file-because-the-file-format-or-extension-is-invalid-quot-opening-office-files.aspx
• I checked file-permissions > I have full access.
• I checked the file extension: It is a normal .xls or .xlsx extension
• I checked the security tab: I have full access. 
• I cleaned out the temp folder. 

But no matter what I try, the issue remains. Anyone other ideas?

Any help is greatly appreciated!

ps: I am using Excel 2013

Answer 3

2015 and the issue still exists. I'm using Office 2010

I have read all the forums it seems like to no avail.

ERROR--

"Excel cannot open the file 'etc.xlsx' because the file format or file extension is not valid. Verify that the file has not been corrupted and that the file extension matches the format of the file."

The file is fine on the sending computer. It appears to get corrupted when it is attached to Outlook and sent.

The receiving computer gets the error. I can open the file all day long on the sending computer.

Even better it is intermittent. Some files are attached to Outlook and sent just fine. Others get corrupted.

I've downloaded the Microsoft security scanner. Came up clean. Tried renaming. Nothing.

I'm at a loss for words. If anybody knows of another fix please let us know!

Answer 4

I am trying to open an xlsx file (I have windows 7) and an error message "cannot open file because the file format or file extension is not valid." I have tried renaming without the x, and also opening in a different version of excel, but the programme will not let me. Any ideas? I'd really appreciate any help!

excel file error and can i show file in corrept so kindly file doesnot open

Answer 5

sovled my problem and excel file is corrept and excel file doesnt open