Errors encountered while the config-reloader sidecar attempts to sync configuration in a given namespace.
As a result, configuration for services such as prometheus or alertmanager maybe stale and cannot be automatically updated.'
Check config-reloader logs and the configuration which it tries to reload.
Usually means new config was rejected by the controlled app because it contains errors such as unknown configuration sections or bad resource definitions.
You can prevent such issues with better config testing tools in CI/CD systems such as: