The vCloud Automation Center pre-migration task does not finish and the pre-migration log states that an aggregate exception error has occurred. This message may indicate that a load balancer processing operation has timed out.

The pre-migration task fails because the load balancer timeout setting does not allow enough time for the task to complete. The log file contains an error similar to the following sample.

System.AggregateException: One or more errors occurred. 
---> Companyname.Cafe.HtmlResponseException: Bad Request (400)

An insufficient load balancer timeout setting may cause the pre-migration task to fail. You can correct the problem by increasing the load balancer timeout setting, for example from 20 seconds to 100 seconds or greater, and rerunning the pre-migration task. After you finish the entire migration process, you can restore your load balancer timeout setting to its previous setting.


Increase your load balancer timeout value to at least 100 seconds. For example and depending on the load balancer you are using, edit the load balancer timeout setting in your ssl.conf, httpd.conf or other Web configuration file.


Rerun the pre-migration task.


When pre-migration is finished, open the log file and verify that the the System.AggregateException error is no longer present.

The pre-migration task completes successfully and the System.AggregateException error is no longer present in the log file.