There was some discussion in this thread, but it may just confuse you more.
https://www.mobileread.com/forums/sho...ighlight=adobe
I think the main thing is to try getting reset at Adobe and start over. Install Adobe DE and make sure that works if purchasing/downloading from a store (or library) other than Sony.
Then install (or uninstall and reinstall) the Sony Library software.
But Jim is on the case, so follow his lead, he's the expert here.