I can't see my filled shapes

Press the 'u' key twice to reveal all modified properties for your shape layer; if you can't see stroke and fill, spin down the properties until you can. Something is either turned off, or your preview settings or GPU acceleration is fouled up. If you can't figure it out, embed a screenshot with all of the properties of the problem shape layer spun down so we can see everything happening in the layer.

Hmm...

Maybe type "M" to see if there is a mask path that needs to be deleted.

Also, try clicking the checkerboard (transparency grid) button to see if the ellipse is showing up black.

Also, try resetting preferences: Press Alt (Windows) or Option (Mac OS) while launching After Effects. You can release the Alt or Option key when the splash screen appears. To reset preferences and plug-in cache at the same time, hold down Control-Shift-Alt (Windows) or Command-Shift-Option (Mac OS) while the application is starting.

I hope this helps.