Microsoft Excel cannot access the file, how to resolve this?

I am using a website, and there is an export function to export a file.
In the past, on a different computer, the export function would result in an Excel file which Excel could open.

This is what the message looks like:
Microsoft Excel cannot access the file
'https://....../file.ibfs?........ .xmh'.
There are several possible reasons:
- The file name or path does not exist.
- The file is being used by another program.
- The workbook you are trying to save has the same name as a currently open workbook.


Using internet Explorer 8, and Office 2010 is installed on the computer.
Internet Explorer 8 is needed on this computer albeit it is old, but needed since a website which is visited requires the older browser.

What can be done in order to correct this so that Excel is able to open the file automatically?
(Currently, if I export the file and save it and change the extension to .xls, I can then open it in Excel.
I want to avoid this and simply have Excel recognize the file being exported and open it, perhaps even without saving it).
Is this possible?

Thanks in advance for your assistance.