It seems that there are some files that need to be removed or in other words please try the below steps to Clean uninstall After Effects.
Please uninstall all the Adobe applications from your machine including Creative Cloud Desktop App, You can download & use App Cleaner for faster uninstallation.
You might not find all the listed files however. Ensure the following folders are renamed or deleted from the system:
~ Files / Folders ~
/Applications/.AdobePatchFiles (hidden, use Go > Go to Folder command)
/[startup disk]/Library/Application Support/Adobe*
After you clear up these files, please download and install Creative Cloud Desktop App from the link below :
Hope it helps.
There is an Adobe Cleaner Application that will remove all the software bits that aren't removed on an uninstall; it turns the hazards of rooting around in system folders into a no-brainer. Sorry that I don't have a link for it, but it IS on this web site.