It suddenly occurs to me that you may be talking about the toolbar icon for
the Format Painter. Correct?
If so, keep in mind that for it to work, you need to have your insertion
point in the formatted text or specific text must be selected. It also has
'limits', i.e. if the selected text contains a mixture of fots, font sizes,
some bold but not all, etc. Format Painter is not going to work effectively.
Double-clicking is not necessary unless you want the Format Painter to
remain active so you can apply the formatting to more than one location. In
fact, if your double-click isn't effective, you actually wind up turning the
feature _off_ with the second click. That could explain the issue.
If not, try going to Tools>Customize--Toolbars, click the name of the
Standard toolbar, then click the reset button & confirm OK in the prompt that
comes up.
HTH |:>)