Error Message problems

Disconnect your device from the USB port

Now restart Adobe Digital Edition and using CTRL-SHIFT-D to deauthorize the computer and select Erase Authorization.

Now  go back to Adobe Digital Edition, Help and Authorize Computer

Now reconnect the device to the USB port

Now select your device in the Adobe Digial Edition and Authorize the device

Now get a library book in the Adobe Digital Edition and then add it to the Device

Hopefully things will work fine.

I hope it helps.