Fingerprint cannot be generated when i tried to add new ssh key

I try to add an SSH key on my gitlab, i paste my complete key (~/.ssh/id_rsa.pub) and I click "add key", but an error appear:

"Fingerprint cannot be generated"

I give granted access to /tmp dir to git user. Each click make a file in /tmp, so the problem is smewhere else...

I tried to upgrade gitlab (v1.6.7 => v7.1.0) but not resolve the problem.

I tried to regenerate ssh key for my user, no result more..

Can you help me?