I have extensive functions in an Excel add-in. From time to time when loading spreadsheets that call functions from the add-in, Excel will get the links all messed up. I haven't work out the trigger. Example:

Assume the add-in has a valid function called func()

A cell initially had "=func(a1)" and everything worked well.

At some point, may be days or week later Excel will mess up the spreadsheets and substitute into the cell ='c:\path\path\addinname.xlxa'!func(a1)

Even though the path is actually correct it will not work and return "#NAME?"

How can I stop Excel trying to be smart and messing it up? I thought the purpose of add ins was to have a file already loaded in memory so paths to physical files was not required.


I had gained some improvements by unchecking for every spreadsheet that uses the addin "Update links to other documents" and "Save external Link Values". But after opening on a new PC previously better behaved spreadsheet are now messing up.

In the end I never want Excel to try to point or link to a file, just assume its loaded and ready to go.