If you haven't done so already, download the Creative Cloud app. From there, go to the Apps list and scroll down to the "Find Additional Apps" list. Just to the right of that text is some blue text that reads "Filters & Versions." Click there and select View Previous Versions. Find After Effects in the updated list and when you click the Install button, it will give you the option to download an older version.
As for your current issue, I would try resetting preferences - Press Ctrl+Alt+Shift while the app is starting (unlikely to help but it's possible) and if that doesn't work, maybe deleting and re-installing the program. That's not good when an empty window shows up!
Thank you for reacting. The problem is, I do have the blue text but it only saids 'Filters' and not 'Versions'...
I already tried downloading Adobe After effects 5 times and it does not seems to help...
Do you have a full CC subscription or just to AE? Also, are you sure you are logged into the same Adobe ID in the Creative Cloud app as when you downloaded the program?
I've seen a few variations of this bug. So sorry it is occurring. Can you work with our agents? I think they will want to troubleshoot 1-1 with you. Please report back with their findings.
This bug should be fixed in the update that released today. See Tim's post about it here. The After Effects CC 2017 update to version 14.2 is rolling out worldwide. It may take a day or so to show up for you depending on where you live. You also may need to log out and back in to your CC app or other funky things to get it to show up.
Please let us know if this works for you.