Web IDE fails with "Error while loading the project data. Please try again." with a 404 to /api/v4/projects/Group.Name/Project

Summary

Just upgraded to gitlab-ce 10.7 (Omnibus on Debian stretch)

Steps to reproduce

Go to any project, click "Web IDE"

Example Project

not reproducible on gitlab.com

What is the current bug behavior?

During Web IDE load, https://gitlab.example.org/api/v4/projects/Group.Name/Project got a 404 Not found. The error bar tells Error while loading the project data. Please try again..

Actually querying https://gitlab.example.org/api/v4/projects/Group.Name/Project respond {"error":"404 Not Found"} while https://gitlab.example.org/api/v4/projects/87 works.

What is the expected correct behavior?

No 404, and the Web IDE working.

Relevant logs and/or screenshots

(Paste any relevant logs - please use code blocks (```) to format console output, logs, and code as it's very hard to read otherwise.)

Output of checks

not reproducible on gitlab.com

Results of GitLab environment info

Expand for output related to GitLab environment info

System information
System:		Debian 9.4
Current User:	git
Using RVM:	no
Ruby Version:	2.3.6p384
Gem Version:	2.6.13
Bundler Version:1.13.7
Rake Version:	12.3.0
Redis Version:	3.2.11
Git Version:	2.14.3
Sidekiq Version:5.0.5
Go Version:	unknown
GitLab information
Version:	10.7.0
Revision:	2011c9b
Directory:	/opt/gitlab/embedded/service/gitlab-rails
DB Adapter:	postgresql
URL:		https://gitlab.example.org
HTTP Clone URL:	https://gitlab.example.org/some-group/some-project.git
SSH Clone URL:	ssh://git@git.example.org/some-group/some-project.git
Using LDAP:	no
Using Omniauth:	yes
Omniauth Providers: saml
GitLab Shell
Version:	7.1.2
Repository storage paths:

• default: /var/opt/gitlab/git-data/repositories Hooks: /opt/gitlab/embedded/service/gitlab-shell/hooks Git: /opt/gitlab/embedded/bin/git

Results of GitLab application Check

Expand for output related to the GitLab application check

$ sudo gitlab-rake gitlab:check SANITIZE=true
Checking GitLab Shell ...
GitLab Shell version >= 7.1.2 ? ... OK (7.1.2)
Repo base directory exists?
default... yes
Repo storage directories are symlinks?
default... no
Repo paths owned by git:root, or git:git?
default... yes
Repo paths access is drwxrws---?
default... yes
hooks directories in repos are links: ...
3/1 ... ok
11/2 ... ok
11/3 ... ok
12/6 ... ok
12/7 ... ok
13/12 ... ok
2/14 ... ok
15/15 ... ok
15/16 ... ok
15/17 ... ok
15/18 ... ok
15/19 ... ok
15/20 ... ok
15/21 ... ok
15/22 ... ok
15/23 ... ok
15/24 ... ok
15/25 ... ok
15/26 ... ok
15/27 ... ok
15/28 ... ok
15/29 ... ok
15/30 ... ok
15/31 ... ok
15/32 ... ok
15/33 ... ok
15/34 ... ok
15/35 ... ok
15/36 ... ok
15/37 ... ok
15/38 ... ok
15/39 ... ok
15/40 ... ok
15/41 ... ok
15/42 ... ok
15/43 ... ok
15/44 ... ok
15/45 ... ok
15/46 ... ok
15/47 ... ok
15/48 ... ok
15/49 ... ok
15/50 ... ok
15/51 ... ok
15/52 ... ok
15/53 ... ok
15/54 ... ok
15/55 ... ok
15/56 ... ok
16/57 ... ok
16/58 ... ok
25/59 ... ok
11/60 ... ok
15/61 ... ok
15/62 ... ok
11/63 ... ok
12/65 ... repository is empty
29/66 ... ok
13/67 ... ok
11/68 ... ok
38/69 ... ok
27/70 ... ok
15/71 ... ok
15/72 ... ok
19/73 ... ok
11/74 ... ok
13/75 ... repository is empty
45/76 ... ok
45/77 ... ok
51/78 ... ok
11/79 ... ok
5/80 ... ok
27/81 ... ok
59/82 ... ok
2/83 ... ok
2/84 ... ok
2/85 ... ok
45/86 ... ok
2/87 ... ok
Running /opt/gitlab/embedded/service/gitlab-shell/bin/check
Check GitLab API access: OK
Redis available via internal API: OK
Access to /var/opt/gitlab/.ssh/authorized_keys: OK
gitlab-shell self-check successful
Checking GitLab Shell ... Finished
Checking Sidekiq ...
Running? ... yes
Number of Sidekiq processes ... 1
Checking Sidekiq ... Finished
Reply by email is disabled in config/gitlab.yml
Checking LDAP ...
LDAP is disabled in config/gitlab.yml
Checking LDAP ... Finished
Checking GitLab ...
Git configured correctly? ... yes
Database config exists? ... yes
All migrations up? ... yes
Database contains orphaned GroupMembers? ... no
GitLab config exists? ... yes
GitLab config up to date? ... yes
Log directory writable? ... yes
Tmp directory writable? ... yes
Uploads directory exists? ... yes
Uploads directory has correct permissions? ... yes
Uploads directory tmp has correct permissions? ... 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: ...
3/1 ... yes
11/2 ... yes
11/3 ... yes
12/6 ... yes
12/7 ... yes
13/12 ... yes
2/14 ... yes
15/15 ... yes
15/16 ... yes
15/17 ... yes
15/18 ... yes
15/19 ... yes
15/20 ... yes
15/21 ... yes
15/22 ... yes
15/23 ... yes
15/24 ... yes
15/25 ... yes
15/26 ... yes
15/27 ... yes
15/28 ... yes
15/29 ... yes
15/30 ... yes
15/31 ... yes
15/32 ... yes
15/33 ... yes
15/34 ... yes
15/35 ... yes
15/36 ... yes
15/37 ... yes
15/38 ... yes
15/39 ... yes
15/40 ... yes
15/41 ... yes
15/42 ... yes
15/43 ... yes
15/44 ... yes
15/45 ... yes
15/46 ... yes
15/47 ... yes
15/48 ... yes
15/49 ... yes
15/50 ... yes
15/51 ... yes
15/52 ... yes
15/53 ... yes
15/54 ... yes
15/55 ... yes
15/56 ... yes
16/57 ... yes
16/58 ... yes
25/59 ... yes
11/60 ... yes
15/61 ... yes
15/62 ... yes
11/63 ... yes
12/65 ... yes
29/66 ... yes
13/67 ... yes
11/68 ... yes
38/69 ... yes
27/70 ... yes
15/71 ... yes
15/72 ... yes
19/73 ... yes
11/74 ... yes
13/75 ... yes
45/76 ... yes
45/77 ... yes
51/78 ... yes
11/79 ... yes
5/80 ... yes
27/81 ... yes
59/82 ... yes
2/83 ... yes
2/84 ... yes
2/85 ... yes
45/86 ... yes
2/87 ... yes
Redis version >= 2.8.0? ... yes
Ruby version >= 2.3.5 ? ... yes (2.3.6)
Git version >= 2.9.5 ? ... yes (2.14.3)
Git user has default SSH configuration? ... yes
Active users: ... 39
Checking GitLab ... Finished

Possible fixes

(If you can, link to the line of code that might be responsible for the problem)