Why is there no option in gitlab to edit files through the control panel?

Question

GitLab

Installed and configured GitLab, I don't see any errors anywhere. The only thing is that there is no way to edit files through the web panel.
Writes: "Your changes could not be committed, because the file has been changed" Google gave
this link: dev.mensfeld.pl/2013/08/gitlab-your-changes-could-...
. Who faced similar? What else can you try?

Details

System information
System: Debian 7.1
Current User: git
Using RVM: no
Ruby Version: 2.0.0p353
Gem Version: 2.0.14
Bundler Version:1.5.2
Rake Version: 10.1.0
GitLab information
Version: 6.5.1
Revision: 6f6f158
Directory: /home/git/gitlab
DB Adapter: mysql2
URL: git.example.ru
HTTP Clone URL: git.example.ru/some-project.git
SSH Clone URL: [email protected]:some-project.git
Using LDAP: no
Using Omniauth: no
GitLab Shell
Version: 1.8.0
Repositories: /home/git/repositories/
Hooks: /home/git/gitlab-shell/hooks/
Git: /usr/bin/git