If you want a Solid to gradually disappear, I think the easiest way to do it it to use the shape tool. Change the Fill Mode to Gradient, click on the gradient discloser triangle and make both colors the same. Create an opacity tag and then drop it’s opacity. While reading this, I know it sounds like that it will take longer but once you’ve done it you will see that it is very easy and provides more control over what you want to do. In my opinion that is. I think this will work better round tripping for you. Hope this is of some help.
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