Unable to load DLL 'Microsoft.Data.SqlClient.SNI.x64.dll'

Question

I have two published environment, Staging and one for live. my published project works in test env. without any issue, but as soon as I deploy it on live env.
I also should mention that Microsoft.Data.SqlClient.SNI.x64.dll exists in \bin after deployment.

I get the following error:

ERROR 2021-06-08 16:45:34,415 455867ms ysomeController MoveNext           - System.TypeInitializationException: The type initializer for 'Microsoft.Data.SqlClient.TdsParser' threw an exception. ---> System.TypeInitializationException: The type initializer for 'Microsoft.Data.SqlClient.SNILoadHandle' threw an exception. ---> System.DllNotFoundException: Unable to load DLL 'Microsoft.Data.SqlClient.SNI.x64.dll': The specified module could not be found. (Exception from HRESULT: 0x8007007E)
   at Microsoft.Data.SqlClient.SNINativeManagedWrapperX64.SNIInitialize(IntPtr pmo)
   at Microsoft.Data.SqlClient.SNILoadHandle..ctor() in H:...\Microsoft\Data\SqlClient\TdsParserSafeHandles.cs:line 19
   at Microsoft.Data.SqlClient.SNILoadHandle..cctor() in H:...\Microsoft\Data\SqlClient\TdsParserSafeHandles.cs:line 17
   --- End of inner exception stack trace ---
   at Microsoft.Data.SqlClient.TdsParser..cctor() in H:...\Microsoft\Data\SqlClient\TdsParser.cs:line 177
   --- End of inner exception stack trace ---
   at Microsoft.Data.SqlClient.TdsParser..ctor(Boolean MARS, Boolean fAsynchronous) in H:...\Microsoft\Data\SqlClient\TdsParser.cs:line 38
   at Microsoft.Data.SqlClient.SqlInternalConnectionTds.LoginNoFailover(ServerInfo serverInfo, String newPassword, SecureString newSecurePassword, Boolean redirectedUserInstance, SqlConnectionString connectionOptions, SqlCredential credential, TimeoutTimer timeout) in H:...\Microsoft\Data\SqlClient\SqlInternalConnectionTds.cs:line 1831
   at Microsoft.Data.SqlClient.SqlInternalConnectionTds.OpenLoginEnlist(TimeoutTimer timeout, SqlConnectionString connectionOptions, SqlCredential credential, String newPassword, SecureString newSecurePassword, Boolean redirectedUserInstance) in 

Answer 1

This method had worked with me 👉 if this file "Microsoft.Data.SqlClient.SNI.x86.dll"
is not exists in this path:
"C:\Program Files (x86)\Microsoft SQL Server Management Studio 19\Common7\IDE"
Steps:
    1.Download the file from this link https://www.mediafire.com/file/z2wjnd8vzg9vdf4/Microsoft.Data.SqlClient.SNI.x86.dll/file
    2.Copy and Past it to "C:\Program Files (x86)\Microsoft SQL Server Management Studio 19\Common7\IDE"
    3.Run the SQL Server Management Studio Management Studio 19 (Worked with me ✔)

Answer 2

I am also facing the same issue. I tried installing sql management 19.1.0 but it dint help and i need to revert to 18.2 version.
I am stuck for very long now , please help

Answer 3

You could try with Repair option instead of uninstallation of SSMS.

For this try to uninstall from Control Panel>Programs and features. You will see option as Repair.

Just do a Repair, it worked for me.