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Título
When configuring Exchange email workflows, you receive the error "The underlying connection was closed: An unexpected error occurred on a receive" -
Descrição
After configuring the Exchange credentials and auto-discover server, clicking "OK" brings up the message "The underlying connection was closed: An unexpected error occurred on a receive".
If you can configure this section, but email workflows do not process (Accept/Reject commands), this can be the same issue.
You may find an entry in the event log stating that the service cannot reach the auto-discover service:
One or more errors occurred., <service account>, Error, 2020, ServiceAction,System.AggregateException: One or more errors occurred. ---> Microsoft.Exchange.WebServices.Data.AutodiscoverLocalException: The Autodiscover service couldn't be located.at Microsoft.Exchange.WebServices.Autodiscover.AutodiscoverService.InternalGetLegacyUserSettings[TSettings](String emailAddress, List`1 redirectionEmailAddresses, Int32& currentHop)at Microsoft.Exchange.WebServices.Autodiscover.AutodiscoverService.GetLegacyUserSettings[TSettings](String emailAddress)at Microsoft.Exchange.WebServices.Autodiscover.AutodiscoverService.InternalGetLegacyUserSettings(String emailAddress, List`1 requestedSettings)at Microsoft.Exchange.WebServices.Autodiscover.AutodiscoverService.GetUserSettings(String userSmtpAddress, UserSettingName[] userSettingNames)at Microsoft.Exchange.WebServices.Data.ExchangeService.GetAutodiscoverUrl(String emailAddress, ExchangeVersion requestedServerVersion, AutodiscoverRedirectionUrlValidationCallback validateRedirectionUrlCallback)at Microsoft.Exchange.WebServices.Data.ExchangeService.AutodiscoverUrl(String emailAddress, AutodiscoverRedirectionUrlValidationCallback validateRedirectionUrlCallback)at Quest.Avalanche.VersionControl.Workflow.EmailWorkflowWorker.<Start>b__1()at System.Threading.Tasks.Task.Execute() -
Causa
This can happen when using specific TLS versions, and .NET can't seem to negotiate the SSL/TLS protocols with the Exchange server. -
Resolução
Add the following registry keys, which will force .NET to use strong protocols instead of negotiating.
[HKEY_LOCAL_MACHINE\\SOFTWARE\\Microsoft\\.NETFramework\\v4.0.30319] "SchUseStrongCrypto"=dword:00000001
[HKEY_LOCAL_MACHINE\\SOFTWARE\\Wow6432Node\\Microsoft\\.NETFramework\\v4.0.30319] "SchUseStrongCrypto"=dword:00000001
Note: Your .NET versions may be slightly different here.
Restart the GPOADmin services after adding this, and attempt to reconfigure the Email Workflows section.