Double click on Illustrator file to show layer not working

Make sure it’s not a vector group issue:
If your Illustrator file was imported as a composition, each layer should come in separately. But if it was imported as footage, AE treats it as one flat image — so double-clicking won’t open it.
👉 Try re-importing: File → Import → File → select AI file → Import As → Composition – Retain Layer Sizes.

Check if the layer is editable:
Some AI layers are locked or empty. Open your Illustrator file and make sure each layer actually has content and isn’t grouped weirdly (AE can be picky about Illustrator groups and clipping masks).

Convert to shape layers (optional but helps a lot):
Select the layer in AE → right-click → Create → Create Shapes from Vector Layer.
Then you can apply the Write On effect directly to the path, which usually works smoother.

Try opening from the timeline:
Instead of double-clicking in the viewer, right-click the layer in the timeline → Open Layer Panel. Sometimes AE just doesn’t open it with a double-click for whatever reason.