Error Loading DLL

[chris]

I keep getting the following error message in excel when I open a particular
file;
"Error Loading DLL".

I have a large template set up, and I update it monthly. I do not always
get the message, which is even more puzzling. When I do get it when trying
to open it, I can not save the file, no matter what I do. This means that if
I need to modify the template, I am unable to save the changes.

Does anyone have an ideas?

Thanks