@JEO PALENCIA
@Tom van Stiphout Your reply didn't work for me. I finally figured out it was because of broken hyperlinks. Here's an easy fix.
- Select the cell, column, row, or sheet with the issue.
- Right click the selection.
- In the dropdown menu, select Remove Hyperlink(s).
In my case, I had to reformat the text that was no longer linked, but I no longer had the "Reference isn't Valid" error.
An alternative is to cut the cells, past them somewhere else using the Paste Values option, which pastes the values as text. Now cut and paste them back where they were originally.