Digital Editions could not connect to activation servers

OK, I found out what my issue is. According to Kobo's website, ADE version 4.0 is incompatible with the kobo ereader. They suggested I use version 3.0 instead. I did so and was able to authorize my computer. I still can't download books to my e-reader, but now the issue is different. As far as I am concerned, I am no longer having the problem stated in this thread and so I am no longer going to post to it. If I can't resolve my issue now, I will post to a different thread to discuss further problems. Thanks to all who looked into this matter.

I am suddenly able to use ADE again, and it is connecting to the internet.  It has mysteriously started working again, as mysteriously as it stopped working.  I don't understand.  I tried everything, and nothing seemed to work.  I tried deleting ADE and re installing it twice without success, so I tried for the third time.  And it seems that third time can sometimes be lucky.

Found this solution on an old thread and it worked sorry don't know how to connect directly so have copied and paste but it worked!!!

So open ADE. Hit Control-Shift-D. This will ask you if you want to get rid of the authorization on this computer.Answer "Yes". Then try again to authorize this computer and this time it will work.

Having the same problem has anybody found an answer

Same here. I opened up the firewall and I got the welcome message when checking that the firewall was open. My clock is set to the correct time. Everything on the internet works except authorization. Documentation says virus protection might be the cause but offers no suggestions on what to do about it.

I have the same issue. Trying to authorize on my Sony Vaio laptop. My internet connection is fine. I have Windows Vista, using Google Chrome, Norton brand security, if any of that matters

I have this problem too.  I have tried a number of suggested solutions, but so far, no luck.