I am developing iphone App on Xcode (Version 10.2.1 (10E1001)) with Mid 2012 Mac book Pro. I am unable to upload the app because Xcode is issuing the following error message:
User has one ios distribution certificate but its private key is not installed. contact the creator of this certificate to get a copy of the private key
I have saved the private key Untitled.p12 on my machine and double clicked. But it is not working.