I am having the same problem. Cookie5 kept asking for my AppleID and password repeatedly. When I went back to the App Store, the list under the "Purchased" tab implied that Cookies5 was not installed. I clicked on "Install" and it appeared to do so, but Cookie5 had the same problem as above. I tried deleting the program and all supporting .plist and other associated files in the Library folder and tried reinstalling, but Cookie5 continued to have the above problem. I tried deleting the program from LaunchPad, and this time received a notice that the program was damaged and to reinstall. Doing so just gave me the unending request for AppleID and password. I finally gave up and found an older version (5.7.8) on a backup and went through the setup process. This version appears to be working. Based on this, the installation problem appears to be associated with version 5.8.1.