In Enforce, after adding a proxy address to the Cloud Proxy Settings field (in System > Settings > General), the DetectionServerController (aka MonitorController in v15.0 and earlier) will not stay running.
Enforce, all versions with Cloud Detection or Cloud Email services
There's no sanity checking in this field, but you should not include the protocol prefix as part of the proxy address - including the "http" breaks the connections MonitorController is making outbound from Enforce, including to the Oracle database.
Delete "http://" from the proxy URL if present, and recycle the DetectionServerController (aka MonitorController).