Replication Failure: An Argument Was Unexpectedly Null in Code Located In Or Called By ‘HttpContent. (4033376)

Replication failures occur on the base image after previously successful incremental snapshots.

Applicable UI Errors:

An unexpected error occurred
An argument was unexpectedly null in code located in or called by 'HttpContent.ReadAsString'

StackTrace:
System.AggregateException: One or more errors occurred. ---> System.ArgumentNullException: Value cannot be null.
Parameter name: source
   at System.Linq.Enumerable.Take[TSource](IEnumerable`1 source, Int32 count)
   at Microsoft.Http.HttpContent.ReadAsString()
   at WCFClientBase.ClientBase.LogResponseError(Uri uri, String method, HttpResponseMessage response)
   at WCFClientBase.ClientBase.GetResponseContract[T](Uri uri, String method, HttpResponseMessage response)
   at WCFClientBase.ClientBase.ExecuteServiceCall[TReturnType,TRequestType](Uri uri, TRequestType request, String method, String knownETag)
   at WCFClientBase.ClientBase.ExecuteServiceCall[TReturnType,TRequestType](Uri uri, TRequestType request, String method)
   at Replay.Core.Client.ReplicationCommunicationCoreClient.SyncRemoteReplicationJob(RemoteSyncReplicationJobRequest requestSync)
   at Replay.Core.Implementation.Replication.Jobs.ReplicationJob.SyncRemoteReplicationJob(TimeSpan syncTimeout, CancellationToken cancellationToken)
   at Replay.Core.Implementation.Replication.Jobs.ReplicationJob.DoJob(CancellationToken cancellationToken)
   at System.Threading.Tasks.Task.Execute()

This issue occurs when replication fails due to insufficient data transfer capacity. To improve throughput, network and timeout settings need to be adjusted.

To resolve the issue, adjust the following registry settings on both the source and target cores:

1. Ensure adequate network bandwidth:

   • Review the Rapid Recovery 6.9 User Guide for performance considerations when replicating data.

   • Refer to the Rapid Recovery Sizing Guide for network recommendations, including NIC specifications and bandwidth requirements.

2. Modify registry settings:

   • Open the Run dialog (Win + R), type regedit, and press Enter.
   • Navigate to HKEY_LOCAL_MACHINE\SOFTWARE\AppRecovery\Core\Replication\ReplicationService.

   • Adjust the following values:

     • VolumeImageSessionTimeout: Change to 01:00:00 (one hour). (Do not set it to 60 minutes; it is ineffective.)
     • RemoteReplicationSyncJobTimeout: Change to 00:30:00 (30 minutes).

     • MaxParallelStreams: Change to 2. (If replication still fails, change to 1 on both cores.)

3. Restart both core machines after making these changes.

If the issue persists, contact Quest Support for further assistance.