ADE will not download ACSM or EPUB

[bake1018]

I have tried everything.  ADE will not download EPUB or ACSM files.  I have tried the free EPUB downloads from Adobe as well as lending from public library.  I have spent hours in support with Mac and Barnes and Noble.  ADE recognizes my Nook Glowlight Plus, however, every time I try to add a file to the library I get this message: E_ACT_NOT_READY  I have deleted and reinstalled ADE on computer as well.  ADE is authorized on all devices. I greatly appreciate any tips and suggestions.  Thanks! 

[Wilhelm0708]

I'm experiencing the same thing on my Samsung Galaxy S10+ - no books are syncing regardless of my attempts to uninstall, deregister, toggle between sync or not.  I have however discovered that 2-factor authentication must be disabled to use ADE or similar.