Question: I installed the Xcode 6 GM seed, and I'm trying to create an IPA file for the first time. After archive success, when I click on the Export button, a window appears saying:

> 
> **Failed to locate or generate matching signing assets**
> 
> 
> Xcode attempted to locate or generate matching signing assets and failed to do so because of the following issues.
> 
> 
> * **Your account already has a valid iOS Distribution certificate.**
> 
> 
> If you have your signing identity on another Mac, you can import a developer profile. You can also revoke the current certificate and request one again.
> 
> 
> 

Here's a screenshot of the error:

![enter image description here](https://i.stack.imgur.com/XJOZQ.png)

Can anybody tell me how to solve this?

Answer: 
In keychain access, -> Show Expired Certificates, then in your login keychain click on expired certificate and delete it. I also had the same expired certificate in my System keychain, so I deleted it from there too.

-> After deleting the expired cert from the login and System keychains,download certificate from below link and open with keychain.

Download <https://developer.apple.com/certificationauthority/AppleWWDRCA.cer> and add it to Keychain access > certificates (which expires on 2023)

this solved my problem
I was able to resolve this issue by renaming the provisioning profile name in member center and refreshing in XCode 6.