In Excel 07 I open a workbook. Save it as a .xlsm workbook. Close it. When
I try to open it back up I get this message:

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

What is causing this? I tried saving it to different locations and I get the
same error.

See my post two posts below yours. I am having the exact same problem.
Hopefully, someone will answer us.

"Bishop" wrote:

> In Excel 07 I open a workbook. Save it as a .xlsm workbook. Close it. When
> I try to open it back up I get this message:
>
> Excel cannot open the file 'myfilename.xlsm' because the file format or file
> extension is not valid. Verify that the file has not been corrupted and the
> file extension matches the format of the file.
>
> What is causing this? I tried saving it to different locations and I get the
> same error.

See my second question on this posted today titled: Can't Open Saved Excel
Files. That should help.

"Spurfan" wrote:

> See my post two posts below yours. I am having the exact same problem.
> Hopefully, someone will answer us.
>
> "Bishop" wrote:
>
> > In Excel 07 I open a workbook. Save it as a .xlsm workbook. Close it. When
> > I try to open it back up I get this message:
> >
> > Excel cannot open the file 'myfilename.xlsm' because the file format or file
> > extension is not valid. Verify that the file has not been corrupted and the
> > file extension matches the format of the file.
> >
> > What is causing this? I tried saving it to different locations and I get the
> > same error.