First off, save a copy!!
On the copy version, go -->microsoft button--> prepare --> edit links.
See what the status of the links is, if not OK, there is an issue (maybe from moving or renaming a file)
In the list, highlight them and one by one, click break link. This will stop the issue of updating links. Once completed, have a look over your sheet CAREFULLY and ensure everything still works, if it does, jobs a good one, if not, there is a required link you have just broken (but you still have working in your original!!)
If something has stopped working, make a note of what no longer functions and look at the look up reference in the original version, this should tell you which WB, sheet and cell(s) is/ are being looked for and you can decide what to do with them.....
Hope this helps!
Stu