Gitlab runner always stuck, although installed and running, messages are inconsistent
I have a project on Gitlab.com, where I try to enable CI with a Windows runner on my personal VirtualBox here in my office.
The Gitlab runner has been unpacked, configured, installed and started on Windows 7 in an elevated command shell. The VirtualBox with this Windows has access to the internet (GitLab's website works fine in my browser).
gitlab-runner --version
:
Version: 10.0.2
Git revision: a9a76a50
Git branch: 10-0-stable
GO version: go1.8.3
Built: Wed, 04 Oct 2017 12:39:07 +0000
OS/Arch: windows/386
The Windows service of gitlab-runner is up and running.
The command gitlab-runner.exe verify
says "Verifying runner... is alive".
Nevertheless the pipeline is pending, the first job (it has 2) says "This job is stuck, because you don't have any active runners that can run this job.", but this particular runner is displayed in "Settings - CI/CD - Runner settings" and shows a green dot there.
After cleaning the runner's work folder, there is no subfolder structure for specific runners anymore. (Those folders were automatically created in this project a few days before this problem occurred.)
It's an open project on gitlab.com, just using a local Windows runner, because I need licenced software to do the build. This is the job in question. EDIT: Same in another project. EDIT 2: Third one, which is a private repo.
I read many documents, but couldn't find anything I was missing.