Someone has already added that key as an access key to a repository.
Muhittin
I'm New Here 
I'm New Here
Those new to the Atlassian Community have posted less than three times. Give them a warm welcome!
1 answer
Nic Brough -Adaptavist-
Rising Star 
Rising Star
Rising Stars are recognized for providing high-quality answers to other users. Rising Stars receive a certificate of achievement and are on the path to becoming Community Leaders.
There's no easy way to work this out because the keys that belong to other accounts should not be shared.
If you shared the key with someone or used it with a different account, you should already know who it is. If someone gave you the key, you will need to ask them.
If you have no luck chasing it down, you can raise a support request with Atlassian, and they can search out the key for you and identify the account you shared it with.
If you don't want to spend ages chasing down the share, you can (and should) create a new key for your account and use that instead.
For a better explanation, see Theodora’s answer on 
Problem adding SSH key: "Someone has already added that key as an access key to a repository."
You must be a registered user to add a comment. If you've already registered, sign in. Otherwise, register and sign in.