After upgrading to 11.7.1`, the Diagnostic Server will not stay up.
The Windows Event Log will show this error under Application for Spotlight:
Stopping the Diagnostic Server. Catastrophic error occurred failed to initialise the Diagnostic Server runtime environment : Persisted value type 'java.io.Serializable' is not the same as the configured value type 'java.lang.String' : Persisted value type 'java.io.Serializable' is not the same as the configured value type 'java.lang.String'