I recently purchased the monthly subscription for After Effects on the Creative Cloud. I purchased this 2 days ago and every time I try to launch After Effects it makes me reinstall the Creative Cloud and After Effects. This is extremely frustrating. I have uninstalled then reinstalled these two items 9 times now. I went to use my programs today (after reinstalling both) It is trying to get me to repurchase my subscription.
Nobody can tell you anything without proper system info or other technical details. Most likiely you simply have a permissions problem on your computer, so the install isn't persistent.