Illustrator files appearing not as sharp in after effects? tried multiple settings still not fixing problem

Nutley  wrote It's interesting reading the comments, I wonder if the majority of people are actually grasping the issue? It's not that it looks a 'little rough' in After Effects, it's that it looks horrible.

There is no bug, but user error is a definite possiblilty. Try this: put the AI layer that is giving you problems in a new composition,  set the composition magnification ratio to 100% or 200% if you have an HR display and the option to fit up to 200% is available,

press S to reveal scale, scale the layer to 1000%, press H to switch to the hand tool and move the comp panel around so you can see an edge, then switch Continuously Rasterize on an off by clicking this switch om the switches column.

if the edge of the graphic does not change from this:

to this:
then the Illustrator layer has a rastor effect applied to it in Illustrator and it was improperly prepared for viedeo production. An example of a rastor effect in AI is Drop Shadow. There are several of them. Open the file in AI and fix it.

If that test works then scale the layer to 100% and set the Magnification Ratio to 800% or more an d take a look at the edge again. If the horizontal or vertical edges are soft like this, then the artwork is not aligned to the pixel grid. You need to either accurately position the artwork in the comp or return to AI and line up the edges with the pixel grid. With the Magnification ratio is above 100% (200% for HR displays) diagonal lines or curves will have aliased edges but horizontal and vertial lines that are aligned to the pixel grid wil have sharp edges.

If you are scaling down artwork that has a thin line you have to make sure that that line is never less than 1 pixel wide. For example, if you have a 4 pixel (or point in AI) line and you scale the layer down to 25%, the line will now be 1 pixel wide. To stay sharp it must be perfectly aligned with the pixel grid and any curves or diagonal lines will soften and probably change color. If thin lines move they will flicker unless they move at precisely a whole number of pixels per frame. That's just how video works.

So, if your vetor artwork does not stay sharp it was either improperly prepared for video production or you have made a workflow error in AE because there is no bug in any current version of AE that causes vector files to behave badly.

show us your illustrator file at 100% with pixel preview turned on and show us your Ae composition at 100%.

Yes I do. Those settings I checked.  And have always had them set that way.