Find And Replace Keeps Trying To Open Files?

I'm copy and pasting many formulas from different worksheets. After pasting, I'm trying to go into each of the cell references and update it to the new worksheet. For example, let's say the cell has a reference to another cell of: ='Worksheet 1'!xx:xx I want change about 50 cells like that at once to ='Worksheet 2'!xx:xx However, every time I pick the Replace feature, either one at a time, or all at once, it opens the Open file dialog box. I've confirmed that it definitely "Finds" everything correctly....it just happens every time on the "Replace".