The scheduler failed to assign job to the runner

我的 runner 安装正常，在 gitlab 上也正常显示，但是它还是报错：The scheduler failed to assign job to the runner, please try again or contact system administrator。我的 gitlab 是 docker 安装的，版本是：gitlab/gitlab-ce:15.1.2-ce.0

The scheduler failed to assign job to the runner, please try again or contact system administrator 这个报错在哪里发生的？