your adobe login info is stored in your oobe folder. something on your computer (eg, av) must be removing/editing one or more files from that folder.
A) Mac OS: /Users/<user folder>/Library/Application Support/Adobe/OOBE
Note: The \Users\<user folder>\Library\ is hidden by default after 10.7.
google enable access to hidden user library files | Mac OS 10.7 and later for instructions on accessing it or check https://helpx.adobe.com/creative-cloud/kb/unknown-server-error-launching-cc.html.
B) Windows: C:\Users\<user folder>\AppData\Local\Adobe\OOBE
Note: The AppData is hidden with Windows default settings.
google Show hidden files, folders, filename extensions | Windows for instructions to show it or check https://helpx.adobe.com/creative-cloud/kb/unknown-server-error-launching-cc.html.