Service Bus subscription creation

Failed creating Service Bus subscription "NAME" with error code: InternalServerError and with message: CorrelationId: 49f92880-ed43-49e1-88c5-c839b8536f84.

Since two days I'm got this error. What's going on?

CODE:

 if (await manager.TopicExistsAsync(sb.TopicPath))
{
   if (!await manager.SubscriptionExistsAsync(sb.TopicPath, sb.Name))                        {
                            await manager.CreateSubscriptionAsync(sb);
                        }
}

Thanks