unable to paste event attributes

[John Quick]

If you’re still unable to paste, go to the clip you’ve applied the brightness effect to, save and name that setting in the effect window, and then apply the named effect to other clips. A little slower than pasting, but pretty fast.
Alternatively, put the clips you want the effect applied to on their own video track (which you can name as a reminder), and apply the effect to the whole track rather than to the individual clips.