Our company is trying to migrate from OnPrime to OnLine our email services. We are using Hybrid migration wizard, when i clicked over Finish button i got the error, see image bellow.

Reviewing the log I found the following:
{ErrorDetail=Microsoft.Exchange.Migration.MigrationServerConnectionFailedException: The connection to the server 'ceb7d730-8fec-40b6-ac37-f7840d8349e5.resource.mailboxmigration.his.msappproxy.net' could not be completed. ---> Microsoft.Exchange.MailboxReplicationService.MRSRemoteTransientException: The call to 'https://ceb7d730-8fec-40b6-ac37-f7840d8349e5.resource.mailboxmigration.his.msappproxy.net/EWS/mrsproxy.svc' timed out. Error details: The request channel timed out while waiting for a reply after 00:00:09.9994290. Increase the timeout value passed to the call to Request or increase the SendTimeout value on the Binding. The time allotted to this operation may have been a portion of a longer timeout. --> The remote server returned an error: (504) Gateway Timeout. --> The remote server returned an error: (504) Gateway Timeout. ---> Microsoft.Exchange.MailboxReplicationService.MRSRemotePer
manentException: The request channel timed out while waiting for a reply after 00:00:09.9994290. Increase the timeout value passed to the call to Request or increase the SendTimeout value on the Binding. The time allotted to this operation may have been a portion of a longer timeout. ---> Microsoft.Exchange.MailboxReplicationService.MRSRemotePermanentException: The remote server returned an error: (504) Gateway Timeout. ---> Microsoft.Exchange.MailboxReplicationService.MRSRemotePermanentException: The remote server returned an error: (504) Gateway Timeout. --- End of inner exception stack trace --- --- End of inner exception stack trace --- --- End of inner exception stack trace --- at Microsoft.Exchange.MailboxReplicationService.MailboxReplicationServiceFault.ReconstructAndThrow(String serverName, VersionInformation serverVersion) at Microsoft.Exchange.Connections.Common.WcfCli
entWithFaultHandling`2.<>c__DisplayClass4_0.<CallService>b__0() at Microsoft.Exchange.Net.WcfClientBase`1.CallService(Action serviceCall, String context) at Microsoft.Exchange.Connections.Common.WcfClientWithFaultHandling`2.CallService(Action serviceCall, String context) at Microsoft.Exchange.MailboxReplicationService.WcfClientWithVersion`2.CallService(Action serviceCall, String context) at Microsoft.Exchange.Migration.MigrationExchangeProxyRpcClient.CanConnectToMrsProxy(Fqdn serverName, Guid mbxGuid, NetworkCredential credentials, LocalizedException& error) --- End of inner exception stack trace --- at Microsoft.Exchange.Migration.MigrationEndpointVerifier.VerifyConnectivity(MigrationEndpointBase endpoint) at Microsoft.Exchange.Management.Migration.MigrationService.Endpoint.TestMigrationServerAvailability.InternalProcessEndpoint(Boolean fromAutoDiscover) IsValid=True Mess
age=The connection to the server 'ceb7d730-8fec-40b6-ac37-f7840d8349e5.resource.mailboxmigration.his.msappproxy.net' could not be completed. Result=Failed SupportsCutover=False}
Mrsproxy is enable in our local exchange server, i can reach our mrsproxy remotely and i can auntheticated too, i disabled and renable the mrsproxy and try again and all the time i got the same error. someone has been the same error and maybe could share the solution please.
Regards
Indalecio Trujillo