ISSUE: Migration steps slow or failing and logs showing an error 'The client and server cannot communicate, because they do not possess a common algorithm'
Last modified:
Overview
While monitoring the progress of migrations, it was noticed that some steps were in a 'failed' state and others are hung in a 'processing' state. The error in the UI is not useful and therefore reviewing the exchange backend logs is required to obtain the real error. Below is an example error of a user on the 'mail archive migration' step. The same error was also found for a user that failed during the Scan Shortcuts step.
Execute_IngestExcOnlineMailbox |user@domain.com ||88 |b8e8d8ff-1234-4e40-b432-430c4bb473c3| ||Error while processing Online Mailbox
EXCEPTION: System.Net.Http.HttpRequestException: An error occurred while sending the request. ---> System.Net.WebException: The underlying connection was closed: An unexpected error occurred on a receive. ---> System.ComponentModel.Win32Exception: The client and server cannot communicate, because they do not possess a common algorithm
Solution
The highlighted portion of the error is indicative of a TLS issue in which case adding the following registry keys to the Bridgehead server(s) followed by a reboot resolved the issue. Simply run these from PowerShell and reboot the server. It is important to do this on any server running the Exchange Module.
Once the server has rebooted, any of the jobs in a 'processing' state will continue without user intervention. Any jobs in a 'failed' state must be 'restarted'.
While monitoring the progress of migrations, it was noticed that some steps were in a 'failed' state and others are hung in a 'processing' state. The error in the UI is not useful and therefore reviewing the exchange backend logs is required to obtain the real error. Below is an example error of a user on the 'mail archive migration' step. The same error was also found for a user that failed during the Scan Shortcuts step.
Execute_IngestExcOnlineMailbox |user@domain.com ||88 |b8e8d8ff-1234-4e40-b432-430c4bb473c3| ||Error while processing Online Mailbox
EXCEPTION: System.Net.Http.HttpRequestException: An error occurred while sending the request. ---> System.Net.WebException: The underlying connection was closed: An unexpected error occurred on a receive. ---> System.ComponentModel.Win32Exception: The client and server cannot communicate, because they do not possess a common algorithm
Solution
The highlighted portion of the error is indicative of a TLS issue in which case adding the following registry keys to the Bridgehead server(s) followed by a reboot resolved the issue. Simply run these from PowerShell and reboot the server. It is important to do this on any server running the Exchange Module.
New-ItemProperty
-Path 'HKLM:\SOFTWARE\Microsoft\.NETFramework\v4.0.30319' -Name
SystemDefaultTlsVersions -PropertyType DWORD -Value 1
New-ItemProperty
-Path 'HKLM:\SOFTWARE\Microsoft\.NETFramework\v4.0.30319' -Name
SchUseStrongCrypto -PropertyType DWORD -Value 1
Once the server has rebooted, any of the jobs in a 'processing' state will continue without user intervention. Any jobs in a 'failed' state must be 'restarted'.