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Hi,
We have the setup for approvals to use Office 365 since a long time. From October '21 we are facing issues with the approvals... Sometimes it works and sometimes not.
We have the below error when it fails
"Failure Sending Mail. Unable to read data from the transport connection; net_io_connectionclosed"
Does anyone have a solution?
I found a solution from the below 2 links
We have NAV 2013 R2 (No CU for this versions after 2018) and OS is Windows Server 2012 R2.
Pasting the steps followed here
Make sure you backup the registry first before attempting to do this.
Also make sure that you have at least Microsoft .NET Framework 4.5.2 installed on the server.
1. First step is to turn on support for TLS 1.2 by creating TLS1.2 Server and Client folders in HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\SecurityProviders\SCHANNEL\Protocols\
-Create Key TLS 1.2. Under it Create 2 keys Client and Server
-For both folders, create a new DWORD value named DisabledByDefault and set the value to 0. Create again a new DWORD value named Enabled and set the value to 1.
2. Browse to HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Internet Settings\WinHttp.
- create a new DWORD value named DefaultSecureProtocols and set the value to 800.
On a 64-bit version, you also need to do it on HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Microsoft\Windows\CurrentVersion\Internet Settings\WinHttp.
3. Browse to HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft.NETFramework\v4.0.30319.
- create a new DWORD value named SchUseStrongCrypto and set the value to 1.
On a 64-bit version, you also need to do it on HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Microsoft.NETFramework\v4.0.30319 .
Once you finished with all the above steps, restart the server. This worked for me
If step 3 does not have the path in registry follow the below steps (which was the case in my test server)
Open PowerShell run as administrator: [Net.ServicePointManager]::SecurityProtocol
Notice the response is Ssl3, Tls
Run the following 2 commands in PowerShell
Set-ItemProperty -Path 'HKLM:\SOFTWARE\Microsoft\.NetFramework\v4.0.30319' -Name 'SchUseStrongCrypto' -Value '1' -Type DWord
Set-ItemProperty -Path 'HKLM:\SOFTWARE\Wow6432Node\Microsoft\.NetFramework\v4.0.30319' -Name 'SchUseStrongCrypto' -Value '1' -Type DWord
Close PowerShell, reopen as admin, run: [Net.ServicePointManager]::SecurityProtocol
Output is: Tls, Tls11, Tls12
Thank you Marcos for pointing in the right direction. I resolved this issue by enabling Tls 1.2 by editing the registry keys.
Restarted the server and so far it seems to be working fine.
Hello,
This is related to Tls1.2. We have had several support requests about this specific error. We usually suggest to take a look here:
Specific cumulative updates includes support for Tls1.2.
The reason why it fails one time and why it does not fail the next time is because it looks like that one time you hit one of the SMTP servers via smtp.office365.com that is not yet requiring Tls1.2 while another time you are not hitting a SMTP server via smtp.office365.com that is already requiring Tls1.2.
Best is to ensure you are running a support release with a CU that includes Tls1.2. There are some other suggestions related to OS and registry keys that may need to be addressed as well.
Thanks.
#1
YUN ZHU
428
Super User 2025 Season 1
#2
Mansi Soni
302
#3
Sagar Dangar, MCP
287
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