It's been observed, after upgrading RR Core Operating system and importing back the "AppRecovery" registry key ,it causes MongoDb to disconnect. From Rapid Recovery Core Log
Failed to set value for the property named Password
System.InvalidOperationException depth 0: Provided value cannot be decrypted. The registry record might be corrupted or taken from another machine. (0x80131509)
at Replay.ServiceHost.Contracts.Configuration.Serializing.SerializedMemberWrapper.ToDecryptedString(String encrypted) +0x27 6000133
at Replay.ServiceHost.Contracts.Configuration.Serializing.SerializedMemberWrapper.SetValue(Object target, Object value) +0xb 600012b
at Replay.ServiceHost.Implementation.Configuration.Serializing.TypeHandlers.DomainObjectHandler.DeserializeMembers(Object container, RegistryKey regKey) +0x96 6000348
Failed to initialize service 'Replay.Core.Implementation.Storage.UserManagement.MongoUserAccountsManager'. It's likely this service will not function properly
System.ArgumentException depth 0: Internal users must be specified (0x80070057)
at Replay.Core.Implementation.Storage.UserManagement.MongoUserAccountsManager.CheckConfigurationIsValid(MongoCredentialsConfiguration config) +0x6d 6000a40
at Replay.ServiceHost.Implementation.Services.ConfigurableService`1.ValidateConfiguration(TConfig config, Action`2 invalidConfigurationHandler) +0x0 6000225
at Replay.ServiceHost.Implementation.Services.ConfigurableService`1.Initialize() +0x2d 600021b
at Replay.ServiceHost.Implementation.Services.ServicesContainer.StartWorkerService(String serviceName) +0x11c 600024a