I'm having the same issue. It was working perfectly yesterday and then when I had two new NetGalley acsm files, I got the E_ADEPT_UNKNOWN error. I've tried uninstalling and reinstalling ADE 4.5 and I've tried erasing authorization and re-authorizing it. I've also tried older versions of ADE and am still getting an error. This is extremely frustrating and based on a search of the forum, it appears that I'm not the only one experiencing problems. Does anyone out there have any idea if there's an available fix? Thank you in advance!
It looks everything is working again, so please disregard my query. Thank you.