Why can't I animate the path of a layer imported from Illustrator?

(note: when i imported the gradient layers they were gray and i had to add a new gradient inside of After Effects so there was certainly a problem)

There is no problem. you simply need to understand that they are two completely different things not compatible with one another. AE merely tried to do you a favor by retaining the appearance and "freezing" the gradients, i.e. making the layers uneditable. As far as that's concerned, everything works as it is intended. the simple answer therefore is to not waste your time by jumping too far ahead in AI, creating incompatible data that AE can't handle but rather trying to create as much as you can in AE from the start.

Mylenium

As angie say's it's not clear, so try to post some screenshot to explain your issue better.

Sorry but it's not clear what you mean.

Are you converting the Illustrator file to Shape layers? This is the approach I'd take as then the artwork is converted to AE shape layers, making it easier to animate properties.

Or, are you animating the Position property path of the layer? If so, you can just copy the path in Illustrator, then paste it into the Position property in AE (You need to have "Preserve Paths" selected in the Clipboard preferences in Illustrator for this to work)

Also, be aware that, when you bring an AI file into AE, it's basically Rasterized and the treated as a bitmap, so Gradients etc are just rendered pixels. If you click on the "Continuous Rasterize" switch in the Timeline, it will then continuously rasterise it, giving the impression of vector art (ie the ability to Scale up without losing resolution) However, all it's doing is doing a new rasterization on each frame. To make truly Vector, you should convert elements to Shape layers.

Gradients are not always rendered reliably in AE. You can change the settings in the Project settings so that they render in better quality (elect the AI file in Project panel, go to File > Interpret Footage > Main. At the bottom you should find the options for this.