little white dots on the timeline near dissolve

[John Pale]

You have dupe detection turned on in your sequence preferences.

The dots are telling you that you have duplicate frames (frames you have used before elsewhere in the timeline) within your transition.

Dupe detection slows down performance…you should turn it off if you dont have a pressing need to have it on.

[Rick Dolishny]

Ah perfect!

I am dissolving from shot A to shot A with a colour effect, so that makes sense.

Thanks for the excellent advice on dupe and performance. I am nearing the end of an online I need it on for a little while. Great work!

– Rick