Index formula suddenly return #REF! error when I try to open the linked workbook.

So I have a workbook titled "Process Library" which assigns a code to a process. Then on my other sheets, I use Index to return the value beside a specific code so that I can go into the Process workbook and make changes to the name on all my workbooks linked to the library rather than go to each one and make changes.

This was working well until a few days ago when all of a sudden, anytime I tried to open the process library, all of my codes would suddenly change to #REF!. This is a huge PITA because I will have to go back and fix the formula on every sheet which references the library.

Any idea why this is happening?

Hi dbl_dbl,

Is the #REF! error concerning the cell, or the entire destination string?

Regards,

J.

The destination string.