Host Unable to Recover from Startup Errors

During startup, it appears that a file error loading host.json can cause the host to go into an unrecoverable state. Logs state that the host has restarted, but the host availability checks fail and incoming requests all return 503s.

See ICM incident https://icm.ad.msft.net/imp/v3/incidents/details/90716615 for details on the affected app including Kusto queries showing the issue.

Review the startup path around host.json loading and the logs described in the issue; use the linked ICM incident's Kusto queries if accessible. Verify that a startup file error leaves the host recoverable, availability checks pass, and incoming requests no longer return 503.

Written by the indexing model from the issue text.