Can't copy markdown snippets

Summary

Copying .md snippets doesn't work.

Steps to reproduce

Create a snippet with a filename ending in .md
Click the copy icon

Expected behavior

I expected a small pop-up which says Copied! and that the raw content of the .md file to be copied to the clipboard but none of that happened.

Relevant logs and/or screenshots

Firefox Web-console output:

18:42:21.560 Error: Invalid "target" value, use a valid Element
[6]</o<.set() application-bb56f416d10e8e01f8b15cebab7ce21c.js:38
[6]</t.prototype.resolveOptions() application-bb56f416d10e8e01f8b15cebab7ce21c.js:38
t() application-bb56f416d10e8e01f8b15cebab7ce21c.js:38
[7]</e.prototype.onClick() application-bb56f416d10e8e01f8b15cebab7ce21c.js:38
[7]</e.prototype.delegateClick/this.binding<() application-bb56f416d10e8e01f8b15cebab7ce21c.js:38
[1]</n.bind/<() application-bb56f416d10e8e01f8b15cebab7ce21c.js:38
1 application-bb56f416d10e8e01f8b15cebab7ce21c.js:38:16145

Output of checks

Results of GitLab Application Check

Checking GitLab Shell ...

GitLab Shell version >= 2.6.10 ? ... OK (2.6.10)
Repo base directory exists? ... yes
Repo base directory is a symlink? ... no
Repo base owned by git:git? ... yes
Repo base access is drwxrws---? ... yes
hooks directories in repos are links: ...
4/1 ... ok
5/2 ... ok
9/4 ... ok
3/6 ... ok
13/14 ... ok
3/16 ... ok
14/20 ... ok
18/21 ... ok
4/22 ... ok
4/25 ... ok
4/26 ... ok
4/27 ... ok
4/28 ... ok
7/29 ... ok
7/30 ... ok
4/33 ... ok
22/36 ... ok
22/38 ... ok
22/39 ... ok
22/40 ... ok
22/41 ... ok
22/42 ... ok
22/43 ... ok
22/44 ... ok
4/45 ... ok
22/46 ... ok
22/47 ... ok
30/49 ... repository is empty
Running /opt/gitlab/embedded/service/gitlab-shell/bin/check
Check GitLab API access: OK
Check directories and files:
        /var/opt/gitlab/git-data/repositories: OK
        /var/opt/gitlab/.ssh/authorized_keys: OK
Test redis-cli executable: redis-cli 2.8.21
Send ping to redis server: PONG
gitlab-shell self-check successful

Checking GitLab Shell ... Finished

Checking Sidekiq ...

Running? ... yes
Number of Sidekiq processes ... 1

Checking Sidekiq ... Finished

Checking Reply by email ...

Reply by email is disabled in config/gitlab.yml

Checking Reply by email ... Finished

Checking LDAP ...

LDAP users with access to your GitLab server (only showing the first 100 results)
Server: ldapmain

Checking LDAP ... Finished

Checking GitLab ...

Git configured with autocrlf=input? ... yes
Database config exists? ... yes
All migrations up? ... yes
Database contains orphaned GroupMembers? ... no
GitLab config exists? ... yes
GitLab config outdated? ... no
Log directory writable? ... yes
Tmp directory writable? ... yes
Uploads directory setup correctly? ... yes
Init script exists? ... skipped (omnibus-gitlab has no init script)
Init script up-to-date? ... skipped (omnibus-gitlab has no init script)
projects have namespace: ...
4/1 ... yes
5/2 ... yes
9/4 ... yes
3/6 ... yes
13/14 ... yes
3/16 ... yes
14/20 ... yes
18/21 ... yes
4/22 ... yes
4/25 ... yes
4/26 ... yes
4/27 ... yes
4/28 ... yes
7/29 ... yes
7/30 ... yes
4/33 ... yes
22/36 ... yes
22/38 ... yes
22/39 ... yes
22/40 ... yes
22/41 ... yes
22/42 ... yes
22/43 ... yes
22/44 ... yes
4/45 ... yes
22/46 ... yes
22/47 ... yes
30/49 ... yes
Redis version >= 2.8.0? ... yes
Ruby version >= 2.1.0 ? ... yes (2.1.8)
Your git bin path is "/opt/gitlab/embedded/bin/git"
Git version >= 1.7.10 ? ... yes (2.6.2)
Active users: 28

Checking GitLab ... Finished

Results of GitLab Environment Info

System information
System:         Ubuntu 14.04
Current User:   git
Using RVM:      no
Ruby Version:   2.1.8p440
Gem Version:    2.5.1
Bundler Version:1.10.6
Rake Version:   10.5.0
Sidekiq Version:4.0.1

GitLab information
Version:        8.5.1
Revision:       8b7080d
Directory:      /opt/gitlab/embedded/service/gitlab-rails
DB Adapter:     postgresql
URL:            <left-out>
HTTP Clone URL: <left-out>/some-group/some-project.git
SSH Clone URL:  git@<left-out>:some-group/some-project.git
Using LDAP:     yes
Using Omniauth: no

GitLab Shell
Version:        2.6.10
Repositories:   /var/opt/gitlab/git-data/repositories
Hooks:          /opt/gitlab/embedded/service/gitlab-shell/hooks/
Git:            /opt/gitlab/embedded/bin/git

Possible fixes

N/A

Admin message