Check to see if the names "Auto_Open" and "Auto_Close" are defined
(Ctrl-F3). They may be pointing to the add-in. Delete them to eliminate
the problem.

For the size problem you might check each worksheet to see if its active
area is larger than the data. Press Ctrl-End to go to the last active cell.
If this is well beyond data try selecting and then deleting the unused rows
and columns. Then save.

--
Jim Rech
Excel MVP