Hi,
Your issue appears to be the same as the following topics:
and:
You will need to contact Blizzard Support and have them look at your account… mind the following words from Blizzard CS here:
If it goes beyond 24 hours, then that means that something else has happened and at that point, submitting a ticket, informing them that you have waited the 24 hours and the account is still showing as in use, then the support agents can investigate further.
Good luck !
I got temp banned, it says I’m already using my own cd key. How could I be. So anyways I keep getting screwed (reinstalling does not fix it) [even if you use different cd-key] wow so after all that fun I deiced to start remodeling my room I cleaned up every nook and cranny whew boy oh boy did I ever get down on my knees and scrub. If you need game update and you play east switch to Asia and it will download. The Asians love Diablo so they treat it with love and care. Damn US Americans got no love for legacy everyone converted to d2 remastered.
Thanks for kicking me off I am addicted to the game it’s so much fun. Guess I need to make a hardcore single player bow amazon. (not as fun)**
** It sucks that there is this “protective feature” to help keep bots away? That plan failed. You’re keeping your own good people out all the while the bots are farming chaos baals. I’m sitting here like a dog at the door waiting for you to let me in. It’s a cold world when there’s nothing anyone can do for me.**
** One nice thing I discovered is, that if I’m tethering my phone to my laptop and Wi-Fi is actively on, it causes this disruption. so, if you turn on usb tether turn off Wi-Fi.**
I do have LOTS of love 
for the blizzard employees and the game masters! I know it’s not your guys fault, and i’m not mad at anyone, I just felt the need to express my trials and errors.
I thank you for your time and look forward to reply!
I also see the same error Your CD key is already in use… So annoying , tried reinstalling and no luck at all.
Did you open a ticket or any idea how to resolve issue? @TrueValkyrie
Yes I have and there is nothing the game masters or anyone can do for me there. I even tried flushing my IP address and renewing it and still locked out. Now it’s been like almost a week. I got a friend running seven bots right now just chillin having a good old time. Me? 100% legit and still get on lock out.
*UPDATE Feb 6th 2023 - Over the weekend there was an issue with our tools that would have allowed us to assist with any 24+ or older CD Key In Use by “your account” That issue has since been resolved and I have gone through and knocked everyone who posted here offline. You should be able to login normally at this time.
If you are still unable to login, please submit a new ticket with those details (screenshots are welcome) along with requested system data:
System Reports: Obtaining System Files - Blizzard Support
WinMTR: Running WinMTR - Blizzard Support
So we can look into your particular situation further.
If you crash or get disconnected your account can become locked for up to 24 hours during which you will receive the message that your account is in use by you. (This is not something we can bypass and is a product of the older platform and service limitations for that older system.)
If it goes beyond 24 hours, then that means that something else has happened and at that point, submitting a ticket, informing them that you have waited the 24 hours and the account is still showing as in use, then the support agents can investigate further.
Do note that currently responses are delayed due to higher than normal ticket volume (WoW Dragonflight Patch) so please make sure you include as much detail as possible to help prevent unnecessary back and forth
I appreciate your support but as of right now the CD Key is still in use.
I have opened a ticket and but the two txt files of DxDiag and MsInfo on the ticket.
I noticed someone said not to try logging on, welp, I checked after your reply facepalm and it is still the same… cant log in.
I guess I will keep waiting.
I have the same problems writing that my CD-key is being used, although I tried to log in from another computer there is no such problem
I have had this issue of my cd key being used for several days now, sent in a ticket and they did not do a thing. Been almost a week of not being able to log in.
Ive had some of these characters almost since diablo 2 was first released. Ive made sure to log into them every month since then whether I was actively playing or not.
I told them i reinstalled , I told them I waited longer then the 24 hours
and still nothing just a reply that basically says Shrug… lost of people are having this problem. We know we are looking into it.
Ill gladly send a new ticket if thats what it takes. Where should I be sending the ticket?
Hello, Artem!
Sorry for the long wait. Azeroth needs surveillance, and our forces do not allow us to react immediately.
I am the game master of Ulmafri, and today I am answering your question
Sorry for these inconveniences. As my colleagues have already written, the developers are working on fixing the error. Making repeated requests to the support service will not speed up the preparation of the fix.
This was answered to me the third time when I wrote to them
Hey, I have the same problem for three days now. I was disconnected from battle.net and told that my key is being used by myself.
Three days after I submitted the ticket, the blizz supporter told me to come here and beg for your help.
If that was not enough, yesterday I bought a new CD-Key for 15€ and now it’s giving me the same message: the key is being used by myself!
What am I supposed to do? Can I at least get my money back or so? 
New key, same message: key is being used by myself. Please fix that
I have the same issue. cd key in use. please resolve this asap. thank you.
fyi, the issue does not seem to be related to our hardware or software setup as many of us were able to log on and play with no issues until recently. the issue is something with the d2 LOD server authentication protocols. are bots the main problem? why not try to reboot the servers, apply any necessary updates, and/or restore the affected accounts? many of us have characters and items we do not want to lose.
thank you for your support and assistance. I may check back but in the meantime have a wonderful day.
I’m getting this same issue that my CD-Key is being used by me. I was connecting to battle.net and accidentally escaped out of the logging in process and now I can’t log in period. Please help.
I actually got an idea. Get a new set of cd key and log on and off every account and every character one has. When you hit the jack pot meaning you logged onto your character that is still logged on your old cd key causing the unable to connect error, log it off with your new cd key and everything should be all set. The old cd key should now not be in use cuz you logged off the key character that’s causing the problem. The only risk to this is that when you log onto the character that’s still logged on, Blizzard might detect that there are 2 different cd keys logged onto the same character and they might permanently ban both your old and new cd keys. In this case maybe “ticket” and tell them you are going to try to find that character that’s still logged on by using a new cd key then log it off and inform Blizzard to please not ban your old and new cd keys while doing this… Or just uninstall old cd key and get a new and different one, but the problem is still that when you log onto the character that’s causing your old cd key the unable to connect error (cd key being used by self) then Blizzard might have a problem with that and ban you, so ticket tell them before you do this should be a must. Tell them your old key and new key and the registered owner name(s) etc etc and it SHOULD be fine.
the third day has passed , it gives the same error that my key is being used when it will be repaired ?
none of those options work
Hey all,
Kershew gave an update on the 6th in their post above.
Anyone who posted before the update, Kershew manually reset those players’ accounts. However, that doesn’t apply to anyone who posted after the update.
Thus, as Kershew stated anyone who still cannot login after the 24 hour period needs to submit a support ticket so that a GM can reset the account.
Hello, I am also still having this issue and it’s been multiple days. I’ve also posted a ticket as well. Hope to get an update on when this can be resolved.
I’ve submitted a ticket and it seems the GMs/Technical staff are stumped too.