The two formats are incompatible.
You cannot pretend that an XLA is an XLL - Excel will notice the difference.

To write an XLL, you need to write it in a language which can compile DLLs -
such as C.

William Hooper has some good info on XLLs at:
http://www.whooper.co.uk/excelstuff.htm


If the XLL functions are used in only one workbook, you could skip the
add-in drama and include the functions in the workbook itself.


--
Rob van Gelder - http://www.vangelder.co.nz/excel


"Matthew Wieder" wrote in message
...
as I said, the initial add-in was an .xll so in order to have a clean
replace, I had to replace the file with the same name. It still works as
an add-in renamed; that doesn't appear to be the problem. Also,
understand, I'm not updating an add-in but replacing it.

Bob Phillips wrote:

Why did you rename it to xll? An xll is a C addin, not VBA. Normally,
when
you update an addin, save it in the same place, and it should then be
available next time you reload Excel.