As I was working on a build server, I ran into an issue importing pfx (assembly signing) files.  I kept getting an error – “Failed to install key pair–Object already exists” trying to run the following command:

sn –I myfile.pfx VS_KEY_XXXXXX

Of course, I have to import my files on build machine in order to perform successful build.  I tried to delete the container, issuing the following command:

sn –d VS_KEY_XXXXXX

I got an error – “Container does not exist”.

I kept on struggling with this issue for a while, but got nowhere.  Then it hit me.  Maybe another user tried to import the same file already?  I logged in as one of the users who also tried to work on the build process. I was able to delete the container.  Then I logged in as the TFS Build service user again and was able to successfully import the PFX file then.  Moral of the story – apparently on Windows Server 2012 you can run into issues if multiple user profile try to import the same PFX file.

I hope this post will save someone some grey hairs.  Mine is practically gone already, so no harm done here.

Enjoy.